Transistors were used for second generation computers and integrated circuits in third generation. First generation computers used vacuum tubes and valves as their main electronic component. Vacuum Tubes were invented by Lee De Forest in 1908.

Pentium is a brand used for a series of x86 architecture-compatible microprocessors produced by Intel since 1993.

The striking feature of modern computer systems is that the dependence on rotating devices is becoming less by the day. The traditional HDD is being replaced by solid state drive which can store data up to a few terabytes. This is a major development in the field of computer-oriented technology. The machines of the previous generation were also fast. True, the speed of modern machines has increased but the major breakthrough areas are—high definition display, cloud computing, Artificial Intelligence and solid state devices inside the computer CPU. 

The current HDD(Hard Disk Drive) capacity range is of the order of terabytes.

The short form for Microsoft Disk Operating System, MS-DOS is a non-graphical command line operating system derived from 86-DOS that was created for IBM compatible computers.

An early form of abacus finds its origin in China.

Android-based hardware was developed in the Fifth Generation. Multimedia, visualization, parallel computing were developed in the Fourth generation but advanced multimedia files were developed in the Fifth Generation.

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.

The machines based on Core i-5 CPU belong to the Fifth Generation.

ENIAC (Electronic Numerical Integrator And Computer) was the world's first general-purpose computer. ENIAC was designed and built for the United States Army to calculate artillery firing tables.