1.The first era Using vacuum tube technology is a punch card.
2.The second, use technology of transistor is a tape. The process is respectively (Sequential Processing).
3.The third age. Using the technology of ICS (integrated circuit, IC) is a magnetic plate is too many programs running at the same time (Multiprogramming) and online (on-line)
4. The fourth age. Using the technology of large-scale integrated circuit (LSI, Large-scale integration) of electric wonchon. Contributions from the microprocessor technology (microprocessor) is said to be a "Computer on a chip" in this era.