• A computer can be described as an electronic calculating device that accepts raw data as input processes it and produces meaningful information i.e. output as result.
• A computer system is made up of both hardware and software components.
• Hardware consists of the physical components of a computer system like input devices, output devices, processing device (CPU) and the storage device.
• Software represents the set of programs and instructions that govern the operation of a computer system.
• A computer is fast, accurate, versatile, reliable, diligent, and has high speed.
• The need for counting and simple computations has led to the development of several computing devices like Abacus, Napier’s bones, Slide Rule, Blaise Pascal’s Adding Machine, Stepped Reckoner, Punch Card System, and Hollerith’s Machine etc.
• The evolution of computers can be divided into five generations. Each generation represents technological evolutions over the period of time.
• A computer has four functional units Input unit, output unit, central processing unit (CPU) and secondary storage unit.
• Random Access Memory is a volatile memory and temporarily holds software, programs and instructions before and after processing.
• Read Only Memory is non-volatile memory whose contents are not lost even after the loss of electric power. It contains startup instructions.
• Secondary memory is also known as external memory or auxiliary memory, and is required to supplement the limited capacity and volatile characteristics of primary memory.
• A Computer has few limitations like they don’t have IQ, they don’t have emotions, they lack decision making power etc.
• Computers play a vital role in every sphere of our life like education, home, entertainment, communication, research, banking, medicine and health and so on.