Learn Basics of Computer usage with Free Lessons & Tips

Definition of Fraud: Noun

"1. Wrongful deception with the intent to gain personally or financially.

2. Intentional deception in order to persuade another person to part with something of value.

3. A person who pretends to be something or someone he is not."

Not to mention the impact that fraud can bring to a company. If you see the types of fraud that is beautifully listed in the link here, It will be clear that a system with a central authority to control and manage will automatically render itself to fraud. Human involvement makes any system vulnerable and when topped with a central authority to process & validate. Fraud is more likely to be in systems where the linkage of products is across many industries.

Let me highlight a use case to explain my point. Let us say, Hafeez, own a famous restaurant that serves meat products that he promises is outsourced organically with no animal trafficking coming into the picture and no illegally sourced meat from unlicensed vendors. As he also promises that all the food products are hygienic and fresh. But to fulfill his promise and the serve the meat outsourced from vendors with confidence the following needs to be ensured in the supply of meat.

Say Jassi, animal farm owner along with 5 others vendors supply to Hafeez for different types of meat required in his restaurant. Before reaching restaurant the meats are transported to processing plants where they are processed and packed and also checked by the authority to verify & certify that it is from legal farm & condition of it is safe to be processed and delivered in the market. In all this process the temperature is a parameter which should be constantly maintained and logged at each step so that the meat is safe to consume.

The above example of a supply chain problem is prone to fraud at many stages. Starting from the first step, the meat can be given to processing plant from unregistered slaughterhouse or animal farm. Well, a smart contract enabled from blockchain technology will be of good use here. Here a smart contract can be made so that it records some necessary details about the meat supplier like name, business id & meat quantity and temperature stored at before leaving the animal farm. This data is checked with the contract conditions and if the supplier is like Jassi who is certified business, then the transaction is recorded on blockchain network.

Now let's say a Logistics company is involved in providing pickup and drop meat from producer to processing plant. Here the main pain point is to ensure that the meats are always under maximum allowed temperature so that it is not spoilt. Traditional IOT technology does help us to monitor temperature, track delivery real-time, but trust is an issue here as logistics companies can tamper with data before pushing it to customers. A blockchain enabled network will not only ensure transparency as it is peer to peer network, the data points created while in transit will be immutable too. Also, an app on Hafeez end can be made to check the delivery details and all notifications/information regarding the shipment. These data will be accessible to authorized people involved in each stage of supply chain and will be auditable.

The above example can be extended to further our discussion. Now processed meat which is packed will bear some information like date and serial number, preservatives used, best before and storing condition specification. Again immutability, transparency which makes data auditable increase trust in the system.  

At the end of the supply chain when meat is received by Hafeez, he being part of the network, he can trace the provenance of the meat and be confident while serving it.

From the above classic problem of the supply chain, It is clear that blockchain provides a trustable, fast, auditable and immutable system that is more resistant to fraud and even if fraud occurs, it gives easy traceability of culprit.

The above example can be replaced with many use case scenarios:

1) Cultivation of Opium for Medical industry and pharmaceutical industry.

2) Exam conduction in a transparent way.

3) Traceability and credibility of diamonds & related gemstone industry.

4) Tenders and process of awarding the contract through blockchain.

5) Judicial proceedings using Distributed ledger technology.

6) Ownership and transfer of assets like cars, land, even cash (fiat currency).

Well, the list is endless and you can cite your favorite use case not mentioned here in comments.Basically, all the processes where people are involved, and central authority to keep a check, fraud is rampant, due to a slow paper-based system and very hard to audit and even when audited and a case of fraud is detected, proving the culprit is very tricky. These inherent drawbacks of the traditional system & corresponding advantages of Blockchain make it defacto system of future in every field where forgery is a big problem.

A Computer is an electronic device that can be instructed to carry out an arbitrary set of arithmetic or logical operations automatically.

1. Introduction:

i. Speed: The speed of computation is very high as the signals pass at the speed of light. Thus, millions of calculations can be done in a second.

ii. Accuracy: As computers work on inbuilt software programs, there is no scope for human errors and are hence, highly accurate.

iii. Information and Storage: A computer can store a large amount of data or instructions in its memory which can be retrieved at point of time.

iv. Other characteristics include: Consistency, Automatic Operation, and Flexibility.

2. Characteristics of Computers:

i. Father of Computer: Charles Babbage

ii. Father of Modern Computer Science: Alan Tuning

iii. First Un-programmable Electronic Digital Computer: Atanasoff Berry Computer (ABC)

iv. First Purpose Electronic Digital Computer: Electronic Numerical Integrator and Calculator (ENIAC)

3. Generations of computers:

a. First Generation (1946 - 1959):

i. Used vacuum tubes & batch processing OS

ii. Machine & Assembly Languages used

iii. Examples: ENIAC, EDVAC, UNIVAC, IBM-701, IBM-650

b. Second Generation (1959 - 1965):

i. Used transistors.

ii. OS: Multi-Bag remaining, Time sharing.

iii. Memory: Magnetic cores, magnetic tapes and disks.

iv. Used assembly and high-level languages like FORTRAN, COBOL, Algol.

v. Examples: IBM 1620, IBM 7094, CDC 1604.

c. Third Generation (1965 - 1971):

i. Used ICs

ii. OS: Remote processing, Time-sharing, Real-time,

iii. Multi-programming

iv. Used High-level languages FORTRAN-II TO IV, Cobol, Pascal PL/1, Basic, Algol-68

v. Examples: IBM-360 series, Honeywell-6000 series, PDP, IBM-370/168

d. Fourth Generation (1971 - 1980):

i. VLSI Circuits Used.

ii. Memory: Semiconductor and Winchester disk.

iii. High level Languages: Fortan 77, Pascal, Cobol used.

iv. Examples: DEC 10, STAR 1000, PDP 11, Super Computers (CRAY-1, CRAY-X-MP).

e. The present generation of computers is the Fifth Generation of computers, i.e. 1980 – till date. The computers use ultra large scale integration (ULSI).

f. High level languages like C++, Java, .NET, etc. are used. Some examples are: laptop, desktop, ultrabook etc.

First of all, a computer is initially designed to compute the data, means it has to do some mathematical and logical operations on the data according to instructions and produce the output at output devices.

Simply we can define a computer is an electronic device which takes input in the form of data from the input devices and process the data and produce output from the output devices.

i. Advantages of using computer:

1. Human effort will be reduced.

2. Time is not wasted.

3. No need of mard copy.

4. High accuracy.

ii. Components of Computer:

1. CPU: Central Processing Unit.

2. Input Devices: Keyboard, Mouse, Scanner etc.

3. Output Devices: Monitor, Printer etc.

There are lot of questions arise while reading about how input devices can communicate with cpu and how cpu displays the output to output devices.

How data is stored in computer and where processing was done?

What is RAM (Random Access Memory)?

What is ROM (Read Only Memory)?

What is Hard Disc?

In order to speak about fundamentals of computer, it's a vast subject, so learn step by step, I will mention about the topics in a simple manner to give some more detailed information about computer in the next lesson.

Polymorphism:

Polymorphism (from the Greek meaning "having multiple forms") is the characteristic of being able to assign a different meaning or usage to something in different contexts - specifically, to allow an entity such as a variable, a function, or an object to have more than one form. There are several different kinds of polymorphism.

A variable with a given name may be allowed to have different forms and the program can determine which form of the variable to use at the time of execution. For example, a variable named USERID may be capable of being either an integer (whole number) or a string of characters (perhaps because the programmer wants to allow a user to enter a user ID as either an employee number - an integer - or with a name - a string of characters). By giving the program a way to distinguish which form is being handled in each case, either kind can be recognized and handled.

A named function can also vary depending on the parameters it is given. For example, if given a variable that is an integer, the function chosen would be to seek a match against a list of employee numbers; if the variable were a string, it would seek a match against a list of names. In either case, both functions would be known in the program by the same name. This type of polymorphism is sometimes known as overloading. In C++, for example, the operator known as the plus sign (+) - which is effectively a simple named function - can be assigned to operate on two objects such that it adds them together (perhaps the most common form of the + operation) or, as in boolean searching, a + can indicate a logical "and" (meaning that both words separated by the + operator must be present in order for a citation to be returned). In another context, the + sign could mean an operation to concatenate the two objects or strings of letters on either side of the + sign. A given operator can also be given yet another meaning when combined with another operator. For example, in the C++ language, a "++" following a variable can mean "increment this value by 1". The meaning of a particular operator is defined as part of a class definition. Since the programmer can create classes, the programmer can also define how operators work for this class of objects; in effect, the programmer can redefine the computing language.

Polymorphism can mean, as in the ML language, a data type of "any," such that when specified for a list, a list containing any data types can be processed by a function. (For example, if a function simply determines the length of a list, it doesn't matter what data types are in the list.)
In PHP, polymorphism means that if B is a descendant of A and a function can accept A as a parameter, it can also accept B.

 Pattern Matching Algorithms:

 There are various algorithms used to implement the pattern matching problem.

Some of them are:

1. Brute Force.
2. Boyer-Moore.
3. Knuth-Morris-Pratt (KMP).

 Brute Force:

 The elements of the array come from a set _ called the alphabet; the elements themselves are called characters. Common examples are ASCII text, where each character is an seven-bit integer1, strands of DNA, where the alphabet is the set of nucleotides {A,C, G, T}, or proteins, where the alphabet is the set of 22 amino acids.

The problem we want to solve is the following. Given two strings, a text T[1 .. n] and a pattern P[1 ..m], find the first substring of the text that is the same as the pattern. (It would be easy to extend our algorithms to find all matching substrings, but we will resist.) A substring is just a contiguous subarray. For any shift s, let Ts denote the substring T[s .. s +m− 1]. So more formally, we want to find the smallest shift s such that Ts = P, or report that there is no match.

For example,if the text is the string ‘AMANAPLANACATACANALPANAMA’2 and the pattern is ‘CAN’, then the output should be 15. If the pattern is ‘SPAM’, then the answer should be ‘none’. In most cases the pattern is much smaller than the text; to make this concrete, I’ll assume that m < n/2. Here’s the ‘obvious’ brute force algorithm, but with one immediate improvement. The inner while loop compares the substring Ts with P. If the two strings are not equal, this loop stops at the first character mismatch.

 ALGORITHM: Brute_Force(T[1 .. n], P[1 ..m]):

For    s

equal 

i 

while equal and i <= m

if T[s + i − 1] != P[i]

equal

else

i

if equal

return s

return ‘none’

Boyer-Moore algorithm:

The Boyer-Moore algorithm (Boyer & Moore 1977) is considered one of the most efficient algorithms for general pattern matching applications. It is able to recognize and skip certain areas in the text where no match would be possible.

The pattern is shifted from left to right across the text, as in brute-force pattern matching, but comparison is performed from right to left on the pattern. As soon as a mismatch is detected, the pattern is shifted to the right according to one of two key heuristics: the extended bad character rule and the good suffix rule.

To illustrate the operation of these heuristics, suppose that the pattern, P, is aligned at position k of T, and that a mismatch has been detected between the character at position i of the pattern that is, P[i] 6= T[k + i − 1]. Then let c = T[k + i − 1], the mismatched character of the text, and t = P[i + 1: : :m], the suffix of the pattern which matches the corresponding portion of the text.

The extended bad character rule proposes that if there is an occurrence of c in P to the left of i,  hat the pattern be shifted so that the two occurrences of c are aligned. If no such shift is possible, the pattern is shifted completely past the c in the text.

The good suffix rule attempts to align the matched suffix, t, with a previous occurrence of t in the pattern (for example, in the pattern reduced, the suffixed occurs twice). If there are no other occurrences of t in the pattern, then the pattern is e shifted so that the a prefix of the pattern matches a suffix of t in the text, or, if this is not possible, shifted completely past t.

The Boyer-Moore algorithm checks both of these heuristics at each stage of the matching process; if both shifts are possible, then the maximum is chosen. In this way, Boyer-Moore achieves so-called `sub-linear' performance for most texts.

To apply the Boyer-Moore algorithm to the permuted output of the Burrows-Wheeler transform, we de_ne an array Hr to relate the characters in T with their position in F, such that 8i : 1 _ i _ n; T[i] = F[Hr[i]]

The Hr array can be computed e_ciently with the following procedure:

Compute-Hr-Array(W; id)

1. i   id

2. for j   1 to n do

3. i   W[i]

4. Hr[j]   i

5. end for

where id is the index of the _rst character in L, obtained from the BWT output.

The Hr array introduces the possibility of accessing random characters in the permuted string. Using this technique, we have implemented a Boyer-Moore algorithm for BWT by adapting a standard Boyer-Moore routine to access character i at F[Hr[i]] instead of at T[i]. The asymptotic complexity is the same for this approach as for Boyer-Moore on uncompressed text, although in practice it is a little slower, due to the time taken to construct Hr, and an extra dereference each time a character is needed.

 KMP String Matching Algorithm: Plan 

• We maintain two indices, ` and r, into the text string.
• We iteratively update these indices and detect matches such that the following loop invariant is maintained – KMP Invariant: ` · r, t[`..r] = p[0..r − `], and all occurrences of the pattern p starting prior to ` in the text t have been detected
• We ensure that the invariant holds initially by setting ` and r to zero.
• Remark: We will see later that the algorithm also requires a preprocessing phase involving only the pattern string p Achieving Linear Time Complexity: The Plan
• The algorithm performs only a constant amount of computation in each iteration
• The algorithm never decreases ` or r
• In each iteration, either ` or r is increased
• Note that the indices ` and r are at most t
• By the KMP invariant, all matches have been detected once ` reaches t, so we can terminate at that point
• The preprocessing phase, which involves only p, runs in O(p) time

KMP Iteration:

• Let’s see how to define an iteration of the KMP loop
• Assume the KMP invariant holds at the beginning of the iteration
• Since the loop has not terminated, ` < t
• We’d like to increase ` or r, while maintaining the invariant
• There are two cases to consider
• Case 1: 0 · r − ` < p, i.e., we do not yet know whether there is a match starting at index `
• Case 2: r − ` = p, i.e., we have found a match starting at index `

Case 1: 0 · r − ` < p

• Case 1.1: t[r] = p[r − `]

– We’ve matched another symbol; increment r

• Case 1.2: r = ` and t[r] 6= p[r − `]

– Our current match is the empty string and the next symbol does not

match p[0]; increment ` and r

• Case 1.3: r > ` and t[r] 6= p[r − `]

– Our current match is a nonempty proper prefix of p and the next

symbol does not extend this match

• – How should we update ` and r in this remaining subcase?

Case 2: r − ` = p

• We output that a match exists starting at index `
• How do we update ` and r?
• Note that this case is very similar to Case 1.3 treated earlier
• We increase ` by p − c(p)

Basic Concepts Of Computer:

1.1 Introduction:

A computer is a programmable machine designed to perform arithmetic and logical operations automatically and sequentially on the input given by the user and gives the desired output after processing. Computer components are
divided into two major categories namely hardware and software. Hardware is the machine itself and its connected devices such as monitor, keyboard, mouse etc. Software are the set of programs that make use of hardware for performingvarious functions.

1.2 Objectives:

• After going through this lesson you would be able to:
• Familiarise yourself with characteristics of computers.
• Identify the basic components of a computer.
• Explain the importance of various units of a computer.
• Differentiate between system software and application software.
• Explain the importance of operating system.
• Get acquainted with open source.
• Appreciate the need of computer security.

1.3 Characteristics of computers:

The characteristics of computers that have made them so powerful and universally useful are speed, accuracy, diligence, versatility and storage capacity. Let us discuss them briefly.

i. Speed:

Computers work at an incredible speed. A powerful computer is capable of performing about 3-4 million simple instructions per second.

ii. Accuracy:

In addition to being fast, computers are also accurate. Errors that may occur can almost always be attributed to human
error (inaccurate data, poorly designed system or faulty instructions/programs written by the programmer)

iii. Diligence:

Unlike human beings, computers are highly consistent. They do not suffer from human traits of boredom and tiredness
resulting in lack of concentration. Computers, therefore, are better than human beings in performing voluminous and
repetitive jobs.

iv. Versatility:

Computers are versatile machines and are capable of performing any task as long as it can be broken down into a
series of logical steps. The presence of computers can be seen in almost every sphere – Railway/Air reservation, Banks, Hotels, Weather forecasting and many more.

v. Storage Capacity:

Today’s computers can store large volumes of data. A piece of information once recorded (or stored) in the computer,
can never be forgotten and can be retrieved almost instantaneously.

1.4 Computer Organization:

A computer system consists of mainly four basic units; namely input unit, storage unit, central processing
unit and output unit. Central Processing unit further includes Arithmetic logic unit and control unit, as shown in
computer performs five major operations or functions irrespective of its size and make. These are:

• It accepts data or instructions as input,
• It stores data and instruction.
• It processes data as per the instructions,
• It controls all operations inside a computer, and
• It gives results in the form of output.

1.4.1 Functional Units:

a. Input Unit: This unit is used for entering data and programs into the computer system by the user for
processing.

b. Storage Unit: The storage unit is used for storing data and instructions before and after processing.

c. Output Unit: The output unit is used for storing the result as output produced by the computer after processing.

d. Processing: The task of performing operations like arithmetic and logical operations is called processing. The Central Processing Unit (CPU) takes data and instructions from the storage unit and makes all sorts of calculations based on the instructions given and the type of data provided. It is then sent back to the storage unit. CPU includes Arithmetic logic unit (ALU) and control unit (CU).

e. Arithmetic Logic Unit: All calculations and comparisons, based on the instructions provided, are carried out within the ALU. It performs arithmetic functions like addition, subtraction, multiplication, division and also logical operations like greater than, less than and equal to etc.

f. Control Unit: Controlling of all operations like input, processing and output are performed by control unit. It takes care of step by step processing of all operations inside the computer.

1.4.2 Memory:

Computer’s memory can be classified into two types; primary memory and secondary memory

a. Primary Memory can be further classified as RAM and ROM.

• RAM or Random Access Memory is the unit in a computer system. It is the place in a computer where the operating system, application programs and thedata in current use are kept temporarily so that they can be accessed by the computer’s processor. It issaid to be ‘volatile’ since its contents are accessibleonly as long as the computer is on. The contents of RAM are no more available once the computer is turned off.

• ROM or Read Only Memory is a special type of memory which can only be read and contents of which are not lost even when the computer is switched off. It typically contains manufacturer’s instructions. Among other things, ROM also stores an initial program called the ‘bootstrap loader’ whose function is to start the operation of computer system once the power is turned on.

b. Secondary Memory:

RAM is volatile memory having a limited storage capacity. Secondary/auxiliary memory is storage other than the RAM. These include devices that are peripheral and are connected and controlled by the computer to enable permanent storage of programs and data. Secondary storage devices are of two types; magnetic and optical. Magnetic devices include hard disks and optical storage devices are CDs, DVDs, Pen drive, Zip drive etc.

• Hard disks are made up of rigid material and are usually a stack of metal disks sealed in a box. The hard disk and the hard disk drive exist together as a unit and is a permanent part of the computer where data and programs are saved. These disks have storage capacities ranging from 1GB to 80 GB and more. Hard disks are rewritable.

• Compact Disk: Compact Disk (CD) is portable disk having data storage capacity between 650-700 MB. It can hold large amount of information such as music, full-motion videos, and text etc. CDs can be either read only or read write type.

• Digital Video Disk: Digital Video Disk (DVD) is similar to a CD but has larger storage capacity and enormous clarity. Depending upon the disk type it can store several Gigabytes of data. DVDs are primarily used to store music or movies and can be played back on your television or the computer too. These are not rewritable.

1.4.3 Input / Output Devices:

These devices are used to enter information and instructions into a computer for storage or processing and to deliver the processed data to a user. Input/Output devices are required for users to communicate with the computer. In simple terms, input devices bring information INTO the computer and output devices bring information OUT of a computer system. These input/output devices are also known as peripherals since they surround the CPU and memory of a computer system.

a) Input Devices:

An input device is any device that provides input to a computer. There are many input devices, but the two most common ones are a keyboard and mouse. Every key you press on the keyboard and every movement or
click you make with the mouse sends a specific input signal to the computer.

• Keyboard: The keyboard is very much like a standard typewriter keyboard with a few additional keys. The basic QWERTY layout of characters is maintained to make it easy to use the system. The additional keys are included to perform certain special functions. These are known as function keys that vary in number from keyboard to keyboard.

• Mouse: A device that controls the movement of the cursor or pointer on a display screen. A mouse is a small object you can roll along a hard and flat surface. Its name is derived from its shape, which looks a bit like a mouse. As you move the mouse, the pointer on the display screen moves in the same direction.

• Trackball: A trackball is an input device used to enter motion data into computers or other electronic devices. It serves the same purpose as a mouse, but is designed with a moveable ball on the top, which can be rolled in any direction.

• Touchpad: A touch pad is a device for pointing (controlling input positioning) on a computer display screen. It is an alternative to the mouse. Originally incorporated in laptop computers, touch pads are also being made for use with desktop computers. A touch pad works by sensing the user’s finger movement and downward pressure.

• Touch Screen: It allows the user to operate/make selections by simply touching the display screen. A displayscreen that is sensitive to the touch of a finger or stylus. Widely used on ATM machines, retail point-of-sale terminals, car navigation systems, medical monitors and industrial control panels.

• Light Pen: Light pen is an input device that utilizes a light-sensitive detector to select objects on a display screen.

• Magnetic ink character recognition (MICR): MICR can identify character printed with a special ink that contains particles of magnetic material. This device particularly finds applications in banking industry.

• Optical mark recognition (OMR): Optical mark recognition, also called mark sense reader is a technology where an OMR device senses the presence or absence of a mark, such as pencil mark. OMR is widely used in tests such as aptitude test.

• Bar code reader: Bar-code readers are photoelectric scanners that read the bar codes or vertical zebra strips marks, printed on product containers. These devices are generally used in super markets, bookshops etc.

• Scanner: Scanner is an input device that can read text or illustration printed on paper and translates the information into a form that the computer can use. A scanner works by digitizing an image.

• Output Devices: Output device receives information from the CPU and presents it to the user in the desired from. The processed data, stored in the memory of the computer is sent to the output unit, which then converts it into a form that can be understood by the user. The output is usually produced in one of the two ways on the display device, or on paper (hard copy).

• Monitor: is often used synonymously with “computer screen” or “display.” Monitor is an output device that resembles the television screen. It may use a Cathode Ray Tube (CRT) to display information. The monitor is associated with a keyboard for manual input of characters and displays the information as it is keyed in. It also displays the program or application output. Like the television, monitors are also available in different sizes.

• Printer: Printers are used to produce paper (commonly known as hardcopy) output. Based on the technology used, they can be classified as Impact or Non-impact printers. Impact printers use the typewriting printing mechanism wherein a hammer strikes the paper through a ribbon in order to produce output. Dot-matrix and Character printers fall under this category. Non-impact printers do not touch the paper while printing. They use chemical, heat or electrical signals to etch the symbols on paper. Inkjet, Deskjet, Laser, Thermal printers fall under this category of printers.

• Plotter: Plotters are used to print graphical output on paper. It interprets computer commands and makes line drawings on paper using multicoloured automated pens. It is capable of producing graphs, drawings, charts, maps etc .

• Facsimile (FAX): Facsimile machine, a device that can send or receive pictures and text over a telephone line. Fax machines work by digitizing an image.

• Sound cards and Speaker(s): An expansion board that enables a computer to manipulate and output sounds. Sound cards are necessary for nearly all CD-ROMs and have become commonplace on modern personal computers. Sound cards enable the computer to output sound through speakers connected to the board, to record sound input from a microphone connected to the computer, and manipulate sound stored on a disk.

1.5 Computer Software:

Computer software is the set of programs that makes the hardware perform a set of tasks in particular order. Hardware and software are complimentary to each other. Both have to work together to produce meaningful results. Computer software is classified into two broad categories; system software and application software.

1.5.1 System Software:

System software consists of a group of programs that control the operations of a computer equipment including functions like managing memory, managing peripherals, loading, storing, and is an interface between the application programs and the computer. MS DOS (Microsoft’s Disk Operating System), UNIX are examples of system software.

1.5.2 Application software:

Software that can perform a specific task for the user, such as word processing, accounting, budgeting or payroll, fall
under the category of application software. Word processors, spreadsheets, database management systems are all
examples of general purpose application software. Types of application software are:

• Word processing software: The main purpose of this software is to produce documents. MS-Word, Word Pad, Notepad and some other text editors are some of the examples of word processing software.

• Database software: Database is a collection of related data. The purpose of this software is to organize and manage data. The advantage of this software is that you can change the way data is stored and displayed. MS access, dBase, FoxPro, Paradox, and Oracle are some of the examples of database software.

• Spread sheet software: The spread sheet software is used to maintain budget, financial statements, grade sheets, and sales records. The purpose of this software is organizing numbers. It also allows the users to perform simple or complex calculations on the numbers entered in rows and columns. MS-Excel is one of the example of spreadsheet software.

Chapters: How Does a Computer Work And Starting Up And Shutting Down:

 1. Write T for True and F for False:

1. CPU is the brain of the computer.

2. The CPU has a device called the Pen drive.

3. Switching on the computer is called booting.

4. While shutting down a computer first switch off the main switch. 

5. When the computer finishes processing, the data we get is called the input.

2. Fill in the blanks:

1. The other devices which is used to store data are called as ____________________________________.

2. The screen that appears on the monitor is called the _______________.

3. There are ______________ steps to Start up the computer.

4. The third step in shutting down a computer is to click on the________________.

5. __________________ is a small storage device that can be carried around easily.

3. Rearrange the steps in correct order to show how a computer is shut down:

1. Click on Shut down ________.
2. Turn off the power switch ________.
3. Switch off the power button on the UPS ________.
4. Switch off the power button on the monitor ________.
5. Click on Turn Off ________.
6. Click on Start ________.

4. Answer the following:

1. What do you mean by processing?

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