The document provides an introduction to computers, including definitions, characteristics, evolution, and components. It defines a computer as an electronic device that processes data according to instructions. Computers are characterized by their speed, accuracy, diligence, versatility, reliability, and multitasking abilities. The document outlines the five generations of computers from vacuum tubes to modern microprocessors. It also includes a block diagram showing the main components of a computer system including the CPU, memory, and input/output devices.

1. 1
Unit 1
Introduction to Computers:

2. Contents
2
 Definition
 Basics of Computer
 Characteristics of computers,
 Evolution of Computer
 Block Diagram Of a computer
 Generations of Computer,
 Classification Of Computers,
 Applications of Computer,
 Capabilities and limitations of computer

3. Definition
 The word compute is derived from the Latin word ‘computare’, was
meaning “arithmetic, accounting”.
 The word computer comes from the word “compute”, which means, "to
calculate”
 Thereby, a computer is an electronic device that can perform
arithmetic operations at high speed
 The Computer meaning is the digital device that stores information
in memory using input devices and manipulate information to produce
output according to given instructions.
3

4.  A computer is also called a data processor because it can store, process,
and retrieve data whenever desired.
 An electronic device that stores, retrieves, and processes data, and can be
programmed with instructions.
 A computer is composed of hardware and software, and can exist in a
variety of sizes and configurations.
 Computer is an electronic device that receives input, stores or processes
the input as per user instructions and provides output in desired format
4

5. Computer Meaning in general term
 Technically, a computer means to calculate or electronic programmable
machine.
 Computer is used to perform some sequence of instructions in fast and
accurate manner. Computer receives input in the form of digitized data,
using input devices like keyboard, mouse, joystick, scanner etc. It process
based on a program instructions to give output.
5

6. Characteristics of computers
6

7.  Speed
 The computer can calculate or perform any task very fast as
compared to the human brain.
 It can perform or execute millions of instructions within a
second.
 The computer has the capability to solve complex computations
within a fraction of a second, whereas the same calculation may
take hours of time for the human.
7

8.  you will be surprised to know that computer can perform
millions of instructions and even more per second.
8

9.  Accuracy
 Computers present a high degree of accuracy.
 Whatever may be the input or instruction given to it by the user;
it will calculate the same and give a meaningful result accurately.
 The degree of accuracy of computer is very high and every
calculation is performed with the same accuracy.
 The errors in computer are due to human and inaccurate data.
9

10.  Diligence
 A human may get tired after continuous hours of work. But, the
computer can work for hours without fatigue or tiredness.
 It never loses concentration for hours of continuous work.
 It can calculate millions of instructions for hours without making
any errors.
10

11.  Versatility
 Versatility is another very important characteristic of computers.
 The computer can work in almost every field of modern human
civilization.
 The computer is used at home for surfing the internet and
multimedia applications such as gaming, watching movies or
online videos, listening to your favorite audio track, and so on.
11

12.  The same computer is used at the office of any organization for
the front office, reception center, preparing presentations for
meetings, or managing payrolls of the employees
 Computers are used on a large scale in the e-commerce industry
for efficient business operation worldwide.
 The versatile use of computers in every field makes it an
inevitable component of the modern digital world.
12

13.  Reliability
 Another characteristic of computers is their reliability.
 The computer delivers a high degree of reliability. That is why
almost everything in this world is computer-driven.
 Today, all the major industries’ business operations all across the
world are performed efficiently using the computer because of its
reliability.
13

14.  The company business is more profitable with the use of a
computer. Because computer helps to perform any task in a very
short time and in a reliable manner.
14

15.  Multitasking
 Multitasking capability of computer is also the major
characteristics of a computer.
 It can have the capacity to perform different types of tasks at the
same time.
 You can surf the internet, at the same time, you prefer to listen to
your favorite music. Simultaneously, you can make a document
in MS word.
15

16.  Storing data
 Computers can store any amount of information after processing
them.
 The stored information can be used by the user in the future.
 The storage media like hard disk, floppy disk, optical disc are
used for storing the data.
 The computer can store a huge collection of data and information
for future reference.
16

17.  Nowadays, the concept of cloud computing has made things
simpler and easier.
 You do not need to bother about the local hard drive capacity of
your computer to store a large amount of data.
 The online storage facility provided by the biggest IT companies
like Google, Microsoft, Amazon, etc. provides the facility for
online cloud storage.
17

18.  No IQ
 The computer doesn’t have its own intelligence.
 It performs its task only when some input is given by the human
(user).
 The computer is dependent on humans to perform any task.
 It always receives instruction or input from the user to execute
the given task efficiently and correctly.
18

19.  It waits for the user input and processes the result based on the
input given to it.
19

20.  No feeling
 The human being has feelings and emotions. Because of this
nature, the performance or working capacity of humans varies
from person to person.
 Unlike a human being, the computer doesn’t have such feelings
or emotions that reflect the performance capability of the
computer.
 Also, the computer does not recognize its user’s mood, whether
he/she is happy or sad.
20

21. Evolution of Computer
 Charles Babbage is considered to be the father of modern digital
computers​
 He designed "Difference engine "in 1822​
 He designed a fully automatic analytical engine in 1842 for
performing basic arithmetic functions​.
 His efforts established a number of principles that are fundamental
to the design of any digital computer.
21

22. Block Diagram Of a computer
22

23. Computer Block Diagram System:
 Mainly computer system consists of three parts, that are central
processing unit (CPU), Input Devices and Output Devices.
 The Central Processing Unit (CPU) is divided into two parts again:
arithmetic logic unit (ALU) and the control unit (CU).
 The set of instruction is in the form of raw data.
 A large amount of data is stored in the computer memory with the
help of primary and secondary storage devices.
23

24.  The CPU is like the heart/brain of the computer.
 The user does not get the desired output, without the necessary
option taken by the CPU.
 The Central processing unit (CPU) is responsible for the processing
of all the instructions which are given by the user to the computer
system.
 The data is entered through input devices such as the keyboard,
mouse, etc.
24

25.  This set of instruction is processed by the CPU after getting the
input by the user, and then the computer system produces the
output.
 The computer can show the output with the help of output devices
to the user, such as monitor, printer, etc.
25

26.  CPU (Central Processing Unit)
 Storage Unit
 ALU(Arithmetic Logic Unit)
 Control Unit
26

27.  Central Processing Unit (CPU)
 The computer system is nothing without the Central processing Unit
so, it is also known as the brain of computer.
 The CPU is an electronic hardware device which can perform
different types of operations such as arithmetic and logical
operation.
27

28. 28

29. Control Unit
 The control unit (CU) controls all the activities or operations which
are performed inside the computer system.
 It receives instructions or information directly from the main
memory of the computer.
 When the control unit receives an instruction set or information, it
converts the instruction set to control signals then; these signals are
sent to the central processor for further processing.
 The control unit understands which operation to execute, accurately,
and in which order.
29

30. Arithmetic and Logical Unit
 The arithmetic and logical unit is the combinational digital
electronic circuit that can perform arithmetic operations on integer
binary numbers.
 It presents the arithmetic and logical operation.
 The outputs of ALU will change asynchronously in response to the
input.
 The basic arithmetic and bitwise logic functions are supported by
ALU.
30

31. Storage Unit
 The information or set of guidelines are stored in the storage unit of
the computer system.
 The storage unit provides the space to store the data or instruction
of processed data.
 The information or data is saved or hold in computer memory or
storage device.
 The data storage is the core function and fundamental of the
computer components.
31

32. Components of Computer System
 The hardware and software exist on the computer.
 The information which is stored through the device is known as
computer software.
 The hardware components of the computer system are related to
electronic and mechanical parts,
 and the software component is related to data and computer
programs.
 Many elements are connected to the main circuit board of the
computer system called a “motherboard.”
32

33. 33

34. These are mainly five components of the computer system.
 Processor.
 Main Memory.
 Secondary Memory.
 Input Devices.
 Output Devices.
34

35. Processor
 The processor is an electric circuitry within the computer system.
 The Central processing unit is the central processor or main
processor of the computer system.
 The processor carries out the instructions of the computer program
with the help of basic arithmetic and logic, input/output operations.
35

36. Main Memory
 The Random Access Memory is the main memory of the computer
system, which is known as RAM.
 The Ram is one of the fastest memory, and it allows the data to be
readable and writeable.
36

37. Secondary memory
 We can store the data and programs on a long-term basis in the
secondary memory.
 The hard disks and the optical disks are the common secondary
devices.
 It is slow and cheap memory as compare to primary memory.
 This memory is not connected to the processor directly.
37

38. Input Devices
 The user provides the set of instruction or information to the
computer system with the help of input devices such as the
keyboard, mouse, scanner, etc.
 The data representation to the computer system is in the form of
binary language after that the processor processes the converted
data.
 The input unit implements the data which is instructed by the user
to the system.
38

39.  We can enter the data from the outside world into the primary
storage as the input through input devices.
 The input devices are the medium of communication between the
outside world and the computer system.
39

40. There are some important features of input devices which
are given below:
1. The input devices receive or accept the data or instruction from the
user, who exist in the outside world.
2. These devices convert the data or instruction into the machine-
readable form for further processing.
3. The input device performs like the connection between the outside
world and our computer system.
4. The keyboard and mouse are common examples of input devices.
40

41. Output Devices
 The output devices produce or generate the desired result according
to our input, such as a printer, monitor, etc.
 All the information sent to the computer once processed is received
by the user through the output unit.
 The output unit displays the data either in the form of a soft copy or
hard copy.
 The printer is for the hard copy.
41

42.  The monitor is for the display.
 The output unit accepts the data in binary form from the computer.
It then converts it into a readable form for the user.
42

43. Generations of Computer,
 Generation in computer terminology is a change in technology a
computer is/was being used.
 Initially, the generation term was used to distinguish between
varying hardware technologies.
 Nowadays, generation includes both hardware and software, which
together make up an entire computer system.
 There are five computer generations known till date.
43

44.  Following are the main five generations of computers.
44
Sr.No Generation & Description
1 First Generation :
The period of first generation: 1946-1959. Vacuum tube based.
2 Second Generation:
The period of second generation: 1959-1965. Transistor based.
3 Third Generation:
The period of third generation: 1965-1971. Integrated Circuit
based.
4 Fourth Generation:
The period of fourth generation: 1971-1980. VLSI
microprocessor based.
5 Fifth Generation:
The period of fifth generation: 1980-onwards. ULSI
microprocessor based.

45.  First Generation Computers
 The period of first generation was from 1946-1959.
 The computers of first generation used vacuum tubes as the basic
components for memory and circuitry for CPU (Central
Processing Unit).
 These tubes, like electric bulbs, produced a lot of heat and the
installations used to fuse frequently.
45

46.  Therefore, they were very expensive and only large organizations
were able to afford it.
 Punch cards, paper tape, and magnetic tape was used as input and
output devices.
 The computers in this generation used machine code as the
programming language.
 In this generation, mainly batch processing operating system was
used.
46

47.  The main features of the first generation are:
 Vacuum tube technology.
 Supported machine language only.
 Very costly
 Generates lot of heat
 Slow input and output devices
 Huge size
 Need of AC
 Non-portable
 Consumes lot of electricity
47

48. 48

49.  Second Generation Computers
 The period of second generation was from 1959-1965.
 In this generation, transistors were used that were cheaper,
consumed less power, more compact in size, more reliable and
faster than the first-generation machines made of vacuum tubes.
 In this generation, assembly language and high-level
programming languages like FORTRAN, COBOL were used.
 The computers used batch processing and multiprogramming
operating system.
49

50.  The main features of second generation are:
 Use of transistors
 Reliable in comparison to first generation computers
 Smaller size as compared to first generation computers
 Generates less heat as compared to first generation computers
 Consumed less electricity as compared to first generation
computers
 Faster than first generation computers
 Still very costly
 AC required
 Supported machine and assembly languages
50

51. 51

52.  Third Generation Computers
 The period of third generation was from 1965-1971.
 The computers of third generation used Integrated Circuits (ICs)
in place of transistors.
 A single IC has many transistors, resistors, and capacitors along
with the associated circuitry.
 The IC was invented by Jack Kilby
 This development made computers smaller in size, reliable, and
efficient.
 In this generation remote processing, time-sharing, multi-
programming operating system were used.
52

53.  High-level languages (FORTRAN-II TO IV, COBOL, PASCAL
PL/1, BASIC, ALGOL-68 etc.) were used during this generation.
53

54.  The main features of third generation are:
 IC used
 More reliable in comparison to previous two generations
 Smaller size
 Generated less heat
 Faster
 Lesser maintenance
 Costly
 AC required
 Consumed lesser electricity
 Supported high-level language
54

55.  Fourth Generation Computers
 The period of fourth generation was from 1971-1980
 Computers of fourth generation used Very Large Scale Integrated
(VLSI) circuits.
 VLSI circuits having about 5000 transistors and other circuit
elements
 Fourth generation computers became more powerful, compact,
reliable, and affordable.
 In this generation, time sharing, real time networks, distributed
operating system were used. All the high-level languages like C,
C++, DBASE etc., were used in this generation.
55

56. The main features of fourth generation are:
 VLSI technology used
 Very cheap
 Portable and reliable
 Use of PCs
 Very small size
 Pipeline processing
 No AC required
 Concept of internet was introduced
 Great developments in the fields of networks
 Computers became easily available
56

57.  Fifth Generation Computers
 In the fifth generation, VLSI technology became ULSI (Ultra
Large Scale Integration) technology,
 resulting in the production of microprocessor chips having ten
million electronic components.
 This generation is based on parallel processing hardware and AI
(Artificial Intelligence) software.
57

58.  AI is an emerging branch in computer science, which interprets
the means and method of making computers think like human
beings.
 All the high-level languages like C and C++, Java, .Net etc., are
used in this generation.
58

59. The main features of fifth generation are:
 ULSI technology
 Development of true artificial intelligence
 Development of Natural language processing
 Advancement in Parallel Processing
 Advancement in Superconductor technology
 More user-friendly interfaces with multimedia features
 Availability of very powerful and compact computers at cheaper
rates
59

60. Classification Of Computers
60

61.  The computer systems can be classified on
the following basis:
1. On the basis of size.
2. On the Type
3. On the purpose.
61

62.  On the basis of size
 Super computers :
 Mainframe computers
 Mini computers
 Micro computers
62

63.  Super computers :
 The super computers are the most high performing system
 A supercomputer is the giant of the computer world.
 It is usually the most expensive and can be afforded by very few
bodies like an organization, countries and research institutions.
 It is used for a lot of mathematical calculations
63

64.  It is an extremely fast computer, which can execute hundreds of
millions of instructions per second.
 For example, weather forecasting, scientific simulations,
(animated)graphics, fluid dynamic calculations, nuclear energy
research, electronic desi.gn, and analysis of geological data .
64

65.  Applications: The uses of supercomputers are dedicated to –
 In research and study of energy and nuclear weapons and
designing the aircraft, airplanes, and flight simulators.
 Climate research and Weather Forecasting and Prediction of
Natural Disasters.
 Spaceship and Satellite Launching.
 Used in scientific research laboratories.
 Used in Chemical and Biological research and for highly
calculation complex tasks.
65

66. Diagram of Super computer
66

67.  Mainframe computers
 Mainframe computers are large computers that have a variety of
networks terminals making it possible for more than one user to
operate on it at the same time.
 Mainframe computers are very expensive to purchase and
maintain.
 These are commonly called as big iron, they are usually used by
big organizations for bulk data processing
67

68.  Applications: Uses of Mainframe Computer –
 Mainframe computers are mainly used by departmental and
commercial organizations like Banks, Companies, Scientific
research centers, and governmental departments like railways.
 These computers can work for 24 hours. Hundreds of users can
work on these computations simultaneously.
 Using the mainframe completes the tasks, Such as keeping
details of payments, research centers, advertising, sending bills
and notices, paying employees, ticket booking, maintaining
details of purchases by users, keeping detailed tax details, etc.
68

69. Diagram of Mainframe computers
69

70.  Mini computers
 Minicomputers are medium sized computers developed in the
1960s.
 It lies in between mainframe and microcomputers.
 they were actually designed for control, instrumentation, human
interaction, and communication switching as distinct from
calculation and record keeping, later they became very popular
for personal uses with evolution.
70

71.  It is a midsize multi-processing system capable of supporting up
to 250 users simultaneously.
71

72.  Applications: The uses of Minicomputers –
 The minicomputers are used as real-time applications in
Industries, bookings, and Research Centers. Banks also use
minicomputers for preparing payroll for employees’ salaries,
records, tracking of financial accounts, etc. As well as in the field
of Higher Education and Engineering.
72

73. Diagram of Minicomputer
73

74.  Micro computers
 This is the commonest computer seen everywhere in Schools for
learning purposes, Offices and homes.
 The Microcomputer derives its name from its use of a
microprocessor (CPU) memory located in one integrated
microchip or circuit.
 Unlike large computers that use more than one chip for its
processing activities.
74

75.  Microcomputers are the smallest in size and they come in
different forms such as Laptop computer, Desktop, Palm Top
computer, Notebook etc.
 Generally, they use one central Processing unit and are usually
used by one person at a time.
75

76.  Applications: The uses of Microcomputer –
 PC is being widely used in many fields like home, office, data
collection, business, education, entertainment, publishing, etc.
 It keeps the details and prepares letters for correspondence in
small businesses, creating bills, accounting, word processing, and
operation of the filing systems in a large company.
76

77.  Classifications of computer-based on data
handling and by type
 Digital computer
 Analog computer
 Hybrid computer
77

78.  Digital computer
 A digital computer deals with the data that can be stored in
binary format i.e. in the form of 0s and 1s.
 The data or information in this computer is stored in voltage
pulses which represent either 0 or 1.
 Any type of data whether it may be a text document, music files,
or graphic images, all are converted into binary format before it
can be stored into a computer’s memory.
78

79.  It is a device that manipulates discrete data and performs
arithmetic and logical functions.
79

80.  Analog computer
 Analog computer is used to process the analog data.
 The analog data is continuously changing or varying data.
 The analog computer is used to measure the continuous varying
aspects of physical quantities like an electrical current, voltages,
hydraulic pressure, or other electrical and mechanical properties.
 Analog computer does not measure the discrete values.
80

81.  Hybrid computer
 A computer that processes both analog and digital data,
 Hybrid computer is a digital computer that accepts analog
signals, converts them to digital and processes them in digital
form.
 he hybrid computer has the capability to process the input in both
the analog and digital formats.
81

82.  The analog portion of the system can handle the continuous
varying aspects of complex mathematical computation, whereas
the digital portion handles the numerical and logical operation.
 hybrid computers are used in medical science to measure the
heartbeat of the patient, also used in controlling industrial
processes and scientific applications.
82

83.  On the Basis of Purposes,
 General Purpose
 Special Purpose
83

84.  General Purpose
 theses computer can store different programs and can thus be
used in countless application.
 A General Purpose Computer can perform any kind of jobs with
equal efficiency simply by changing the application program
stored in main memory.
84

85.  Special Purpose
 A Special Purpose Computer is the one that is designed to
perform only one special task.
 The program or instructions set is permanently stored in such a
machine.
 It does its single task very quickly and it cannot be used for any
other purpose.
 These computers are often used to perform specific function such
as controlling a manufacturing process or directing
communications.
85

86. Applications of Computer
 Home
 Medical Field
 Entertainment
 Industry
 Education
 Government
 Banking
 Business
 Arts
 Science and Engineering
86

87.  Home
 Computers are used at homes for several purposes like online bill
payment, watching movies or shows at home, home tutoring,
social media access, playing games, internet access, etc.
 They provide communication through electronic mail.
 They help to avail work from home facility for corporate
employees.
 Computers help the student community to avail online
educational support.
87

88.  Business
 A computer has high speed of calculation, diligence, accuracy,
reliability, or versatility which made it an integrated part in all
business organizations.
 Computer is used in business organizations for: Payroll
calculations, Sales analysis, Budgeting, Financial forecasting,
Managing employees database and Maintenance of stocks etc.
88

89.  Education
 Computers have its dominant use in the education field which can
significantly enhance performance in learning.
 Even distance learning is made productive and effective through
internet and video-based classes.
 Researchers have massive usage of these computers in their work
from the starting to till the end of their scholarly work.
89

90.  Banking
 Today banking is almost totally dependent on computer. Banks
provide the facilities of:
 Banks provide online accounting facility, which includes current
balances, deposits, overdrafts, interest charges, shares, and trustee
records.
 ATM machines are making it even easier for customers to deal
with banks.
90

91.  Insurance
 Insurance companies are keeping all records up-to-date with the
help of computers.
 The insurance companies, finance houses and stock broking firms
are widely using computers for their concerns.
91

92.  Communication
 Communication means to convey a message, an idea, a picture or
speech that is received and understood clearly and correctly by
the person for whom it is meant for.
 Some main areas in this category are: Chatting, E-mail, FTP,
Video-conferencing and Telnet.
92

93.  Health Care
 Most of the medical information can now be digitized from the
prescription to reports.
 Computation in the field of medicine allows us to offer varied
miraculous therapies to the patients. ECG’s, radiotherapy wasn’t
possible without computers.
93

94.  Military
 Computers are the main tools which help in developing missiles
and other equipment in the deference system.
 Designing and the maintenance are possible only through
computers.
 Computer builds the links between the soldiers and commanders
through the satellite.
94

95.  Construction of weapons and controlling their function is not
possible without the aid of computers.
 The list of the criminals and the records of the cops are
maintained regularly in the system.
95

96.  Entertainment
 Computers help to watch movies online, play games online;
 act as a virtual entertainer in playing games, listening to music,
etc.
 MIDI instruments greatly help people in the entertainment
industry in recording music with artificial instruments.
 Videos can be fed from computers to full screen televisions.
Photo editors are available with fabulous features.
96

97. limitations of computer
 No Self-Intelligence. Computer does not have intelligence of its
own to complete the tasks. They give wrong output if the input
given by humans are wrong.
 No Thinking and Decision Making Power. The computer cannot
think itself.
 No Feeling. Lack of feeling is another limitation of computer.
 It does not hold intelligence of its own. Its IQ level is zero, till
date.
 They have to be told what to do. It has to be instructed on what it
must do and in what sequence.
 A Computer cannot take decisions on its own.
97

98.  Human beings can make certain judgments in our day to day life
based on our feelings, taste, knowledge and experience. It also
lack of emotions, so it will not make certain judgments like
human.
 They cannot perform anything outside the defined scope.
98

99. Thank you
99