Computer generations are based on when major technological changes in computers occurred, like the use of vacuum tubes, transistors, and the microprocessor. As of 2020
The first generation of computers used vacuum tubes as a major piece of technology. Vacuum tubes were widely used in computers from 1940 through 1956.
The second generation of computers saw the use of transistors instead of vacuum tubes. Transistors were widely used in computers from 1956 to 1963.
The third generation of computers introduced the use of IC (integrated circuits) in computers. Using IC's in computers helped reduce the size of computers even more than second-generation computers, and also made them faster.
The fourth generation of computers took advantage of the invention of the microprocessor, more commonly known as a CPU. Microprocessors,
The fifth generation of computers is beginning to use AI (artificial intelligence), an exciting technology with many potential applications around the world.