A computer is a programmable electronic device that can process, store and retrieve data. The data is processed by a set of instructions termed a program. All computers consist of two basic parts, namely, hardware and software.

The number of transistors per unit area has been doubling every 2 years over the last 30 years. This amazing progress in circuit fabrication is known as Moore’s Law, after Gordon Moore (one of the founders of Intel). This trend was originally described by Moore in his 1965 paper [Mor:65] and refined further in the 1970s.