• A computer can thus be defined as a device that can perform both arithmetic and non-arithmetic operations accurately on given data or information at a high speed.• The set of instructions, which directs the computer to produce a desired result, is called a program. Thus a computer system is essentially driven by a program• In technical terms: a computer is a device that is designed to accept and store input data, process it and produce desired results under the direction of the instructions written in the program.
Characteristics of Computers1. Speed: today the speed is over 80,000 MIPS.2. Accuracy: All computer systems besides having amazing speeds have nearly 100% accuracy.3. Reliability: Reliability of any computer system is typically as high as 99.99%.4. Memory: is the electronic holding place for data and instructions.5. Storage: various computer media can hold billions of bytes of data.
Applications of Computers• Schools: Computer Based Training (CBT)• Medicine and Hospital administration: storing medical records of patients for future reference.• Railways and airlines ticketing: railway and airlines ticket booking is done entirely through computers• Banks: ATM (Automatic Teller Machine) and modern banking system.• Scientific and engineering applications: designing of bridges, multi-storied buildings, automobiles etc.• Business and administrative applications: payroll processing, inventory control, sales analysis and forecasting, word processing, census, questionnaire analysis etc.
• Avionics and Space flights: modern aircraft can fly only with the aid of an onboard computer. Most modern aircraft have a facility known as autopilot which can take the control of most of the operations of a pilot.• Humanities: used extensively in field such as archaeological research, music analysis and composition, graphic art and linguistics.• Police Work: use computer for maintaining their records, which make it easier to fight crimes.• Metrology: use to predict weather, rainfall and monsoon patterns in the country• Entertainment: special effects of movies, computer assisted pictures. Composing, editing etc.