Generations of computer


A computer is derived from word computing which means to calculate. A computer is an electronic machine or device which helps in doing arithmetic or non-arithmetic operations, processing data with the help of programs to solve a given problem. It is mainly used for data processing. Between input and output, there is processing that carries out calculations on data.

In various fields, especially business and industry the primary function of the computer is processing data. Other functions are manipulating the data, summarizing the data, storing the data, performing operations on the data, etc. Now comes generations of computers which are 5 in number.


When the first computer was invented in 1944 since that time the size of the computer has decreased whereas speed, reliability and other features of the computer has increased with the passage of time. Generation in computer talk is a step ahead in technology and provides a framework for the growth and development of the computer industry. Originally the term generation was used for differentiating between varying hardware technology but nowadays it has extended its meaning to include both hardware and software which together makes up the entire computer system.

There are 5 generations of computers known to date which are discussed below in detail. Depending on the technology used they are classified as follows-

First Generation1942-1955Vacuum Tube
Second Generation1955-1965Transistors
Third Generation1965-1975Integrated Circuit
Fourth Generation1975 to PresentMicroprocessor
Fifth GenerationIn progressArtificial Intelligence


First-generation computers made use of a vacuum tube for circuitry, magnetic drums were used for storing memory and were very enormous often taking up entire rooms. They were very expensive, also consumed a great amount of electricity, generated a lot of heat which mainly caused malfunctions. They relied on machine language to perform operations and could solve only one problem at a time.

 generation of computer

ENIAC, EDVAC, EDSAC, etc. are examples of first-generation computing devices that were made possible by the invention of vacuum tube. It was a fragile glass device that can control and amplify electronic signals. The vacuum tube computers are known as first-generation computers.


  • Vacuum tubes were the only electronic elements available during that time period.
  • Vacuum tube technology was the only one that made possible the advent of electronic digital computers.
  • All these computers were the fastest calculating device of that time and could perform operations or calculations in milliseconds.


  • Too heavy in size
  • Less reliable
  • A huge amount of heat generated
  • Air conditioning needed
  • Frequent hardware failure
  • Constant maintenance
  • Non-portable
  • Costly


Second-generation computers made use of transistors which acted as a replacement to vacuum tubes. It allowed computers to become faster, more reliable, smaller than first-generation, more energy-efficient, and tried to overcome the disadvantages that were faced by using first-generation computers. The transistor is a device that is composed of semiconductor material that amplifies signals and opens or closes the circuit. Second-generation computers moved from machine language to assembly language which allowed the programmers to specify instructions in words. Second-generation computers made use of high-level programming languages like COBOL and FORTRAN.

Example of second generation computers are IBM 7074 series, CDC 164, IBM 1400 series.

 generations of computer
IBM 7070


  • Smaller in size compared to first-generation
  • More reliable
  • Less heat generating
  • Reduce calculation time from milliseconds to microseconds
  • Fewer hardware failures
  • Better portability
  • Fast in speed
  • Less expensive
  • Use of programming language


  • Constant maintenance required
  • Air conditioning required
  • Can not be used as personal systems
  • Preferably used for commercial purposes.


Third-generation computers made use of the integrated circuits. Transistors got miniaturized and were placed on silicon chips which were semiconductors and helped in increasing the speed and efficiency of computers. In place of punched cards and printouts now users started interacting through keyboards and monitors. They interfaced with an operating system that allowed computer systems to run many different applications at one time with the central program which monitored the memory. Computers became accessible to mass audiences for the first time since they were smaller and cheaper than the predecessors which made use of vacuum tubes and transistors. So the computers which made use of IC technology were referred to as third-generation computers.

Examples of third-generation computers are IBM 360, IBM 370, PDP 8, DEC, UNIVAC 1108, UNIVAC 9000.

generations of computer
IBM System/370


  • Smaller in size compared to previous generations
  • More reliable
  • Lower heat generated than second-generation too
  • Able to reduce calculation time from microseconds to nanoseconds
  • Low maintenance cost
  • Rare hardware failure
  • Easy portability
  • Total general purpose
  • Less power requirement
  • Less cheap


  • Air conditioning required in few cases
  • Highly sophisticated technology required


Fourth-generation computers made and are making use of microprocessors. This technology-packed about 100000 transistors in a single chip. The system that filled an entire room in first-generation can now fit in the palm of the hand. IBM was the company that introduced the first computer for home users in 1981. Apple introduced Macintosh in 1984. Now, these small computers became very powerful and can be linked together with each other to form a network. This eventually leads to the invention of one of the most important developments in today’s world that are the Internet. This generation also saw the development of the Graphical User Interface, mouse, and various handheld devices.

Examples of fourth-generation computers are Intel processors, AMD processors based machines.

 generations of computer


  • Smallest in size
  • Very much reliable
  • Negligible heat generating
  • No air conditioning required
  • Much faster than previous generations
  • Negligible hardware failure
  • Minimal maintenance required
  • Easiest portability
  • Can be used for general and personal purpose
  • Cheapest among all generations


  • Use of very highly sophisticated technology.


Fifth-generation computers will make use of artificial intelligence. This generation is still in development in India. Though some of its applications are used today in India like voice recognition. The use of superconductors and parallel processing is aiding in making artificial intelligence a reality. It will be designed in a way that will be able to perform several functions simultaneously. It will not only be able to perform data processing but knowledge processing also. It will behave like an expert in all things. It will be equipped with the Knowledge Processing Information System. Molecular and nanotechnology and quantum application will change the face of computers in years to come. Fifth-generation computers will be making use of ULAIC technology and Artificial Intelligence.



  • Program Independent
  • Will be able to think and analyze on its own
  • Use of voice recognition
  • Biometric devices
  • Self Organisation and learning

So this is all that one should know about the generation of computers as having knowledge in today’s world is very important.

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