The Computer is one of the essential parts of our daily lives nowadays. It can perform so many tasks automatically, according to the input given to them. Computers were not like this before. There were constant developments and innovations in Computer technology that made Computers so useful, powerful, and cheap to buy.

In Computer terminology, Generation is a change and development in technology. So all such developments and changes are divided into different generations of Computers. Each generation of Computers has brought significant advances in power and speed to perform various tasks. 

The journey of the development of Computer technology started around the 1940s. In 1946 the evolution of technology began with the first generation of Computers and continuously evolving until today. 

Each generation of Computers is designed based on new technological development, resulting in better, cheaper, and smaller computers that are faster, more powerful, and more efficient than their predecessors.

Now there are five generations of Computers. In this article, we will discuss each of these generations of Computers with the necessary details.

First Generation: Vacuum Tubes Era (1946-1958)

The first generation of Computers was from 1946 to 1958. This is the earliest generation of Computers. The Computers of the first generation used vacuum tubes as the essential components for memory and circuitry for the central processing unit (CPU). 

These tubes, like electric tubes, produced a lot of heat and were prone to the frequent fusing of the installations. 

Therefore, they were costly and could be afforded only by large organizations. In this generation, Computers used machine language, the lowest-level programming language, so that it could easily be understood and processed by Computers. 

The most well-known example of the first generation Computer is the Electronic Numeric Integrated and Calculator (ENIAC). Other examples include Manchester Mark 1, Mark 2, Mark 3, UNIVAC, EDVAC, EDSAC, IBM-650, IBM-701, etc.

Advantages of First Generation Computers

• In first-generation Computers, vacuum tube technology was used.
• Because of the use of machine languages, the Computers of the first generation were faster than in early development.
• First-generation computers were fast and were able to calculate data in milliseconds.

Disadvantages of First Generation Computers

• Computers of this generation were huge and could also cover an entire room.
• They heated very quickly due to the consumption of a large amount of electric energy and required a cooling system like AC.
• First-generation computers were not reliable.
• These computers were not portable.
• They had limited programming capabilities.
• They used magnetic drums, which provide significantly less data storage.

Second Generation: The Transistors Era (1959-1964)

The second generation of Computers started from 1959 to 1964. In this generation, transistors were used. Second-generation computers were cheaper, consumed less power, were more compact, more reliable, and faster than the first generation machines made of vacuum tubes. 

In this generation, vacuum tubes were replaced by transistors. In this generation, for memory requirements, magnetic cores were used as primary memory, and magnetic tapes and magnetic disks were used as secondary storage devices in Computers. 

Assembly language and high-level programming languages like FORTRAN and COBOL were used in this generation.

The most famous Second-generation Computers were CDC-3600 and IBM-7094. Other examples include UNIVAC-1108, IBM-7070, IBM-1400, CDC-1604 series of Computers, Honeywell-400, IBM-7000, IBM-1600 series, etc.

Advantages of Second Generation Computers

• The use of a transistor makes the second generation Computer smaller than the first generation Computer.
• Computers of this generation were more reliable.
• Consume less energy and are not heated as compared to the first one.
• Calculate data in microseconds with better speed.
• Computers of this generation could store instructions in memory due to magnetic core technology.

Disadvantages of Second Generation Computers

• Second-generation computers still needed a cooling system.
• The cost of the Computer was still high, however less than the first generation Computer.
• Required maintenance at regular intervals.
• Punch cards were used for input.
• Only used for specific objectives.

Third Generation: Integrated Circuits (1965-1971)

The period of this generation was 1965 to 1971. In this generation, integrated circuits (ICs) were used in place of transistors, and the ICs were invented by Jack Kilby. 

This development made Computers reliable, efficient, and smaller in size than the previous generation due to the smaller size of integrated circuits. 

In this generation, advanced input-output devices, such as keyboards, monitors, mouse were introduced. Before these devices, Computers used punch cards. 

Third-generation Computers used higher-level languages such as PASCAL PL / 1, COBOL, BASIC ALGOL-68, FORTRAN-II TO IV, ETC.

Family series and IBM-360 are the best examples of third-generation Computers. 

Other examples include Honeywell-6000 series, ICL 2900, PDP-11, TDC-316, PDP-8 etc.

Integrated circuits are still used in today’s generation of Computers.

 Advantages of Third generation Computers

• Third-generation computers were smaller in size than their predecessors
• More reliable than the previous one.
• Consumed less energy as compared to the previous generation.
• Generate less heat as compared to the prior generation of Computers.
• Third-generation computers are portable and available for commercial use at relatively low costs.
• Used mouse and keyboard for input.

Disadvantages of Third Generation Computers

• This generation of Computers also required a cooling system.
• The maintenance and production of integrated circuits (ICs) require highly sophisticated technology.
• The price of third-generation Computers was still high for personal needs.

Fourth Generation: The Microprocessor Era (1971-Present)

The fourth generation was developed using the microprocessor as the main component of the technology. 

Microprocessors were also based on very-large-scale integration (VLSI) and large-scale integration (LSI) technologies, and they were developed by assembling several integrated circuits on a single silicon chip. 

VLSI circuits having about 5000 transistors and other circuit elements and their associated circuits on a single chip made it possible to have microComputers of the fourth generation.

Fourth-generation Computers are more affordable, reliable, and powerful due to their compact size. During this generation, Computers became available for personal use. As a result, it gave rise to the PC(Personal Computer) revolution.

In this generation, high-level languages like C, C+, C++, DBASE, etc., were used. Time-sharing, real-time networks, and distributed operating systems were also used.

The most popular Computers of the fourth generation are the IBM-5100, Altair-8800, and Micral; other examples include IBM-4341, STAR-1000, CRAY-1, CRAY-X-MP, PDP-1, DEC-10, etc.

Microprocessors are still in use in today’s technology, but they are not considered a core technology in the fifth generation.

Advantages of Fourth Generation Computer

• Fourth-generation Computers are more powerful, affordable, and reliable than previous generations.
• More storage availability.
• It is smaller in size than the previous one.
• Widely available for commercial and personal use.
• The heat produced was almost negligible, and hence the air conditioner system was no longer needed.
• Fast processing power with less energy consumption.
• It is the cheapest among all generations.
• High-level languages can be used in this type of Computer.

Disadvantages of Fourth Generation Computer

• Microprocessors and VLSI circuits construction require the latest and highly sophisticated technology.
• Instead of an air conditioning system, a cooling fan was included in Computers. Intense use of Computers and these cooling fans made noises.

Fifth Generation: AI (Present & Beyond)

Fifth-generation Computers are based on Ultra Large scale Integration (ULSI) Technology, Artificial intelligence (AI) software, and parallel processing hardware.

AI is an emerging branch in Computer science, which interprets means and methods of making Computers think like human beings. In this generation, all high-level languages are supported. Such languages include C, C++, Java, .NET, etc. 

In the fifth generation, Computers are mainly based on massively parallel computing and logic programming. Fifth-generation Computers include Laptops, desktops, notebooks, ultrabooks, Chromebook, tablets, etc.

Advantages of Fifth Generation Computer

• Fifth-generation Computers are much faster than previous Computer generations. 
• Much smaller in size than other generation Computers
• Portable and easy to use for both commercial and personal purposes.
• Advancement in superconductor technology and also advancement in parallel processing.
• Fifth-generation Computers are almost 100% accurate in calculations.
• Fifth-generation Computers have become so smart with the use of Artificial Intelligence.
• They can understand human languages and recognize pictures of things and individuals.
• The huge development of storage.

Disadvantages of Fifth Generation Computers

• Fifth-generation Computers replaced humans in various fields because of their advanced features and accuracy and reduced jobs.
• It negatively affects the environment. Due to the widespread use of Computers in the fifth generation, the amount of wastage of Computer parts increases day by day.
• Personal and business details and an individual’s privacy are not secure, and various types of cybercrimes can damage personal information and cause financial losses.