WHAT IS COMPUTER ? A Computer is widely used electronic device that takes raw data as input through input devices such as keyboard, mouse and process and gives meaningful result as output through output devices (printer, monitor etc Monitor The screen of the computer. It shows output like text, images and videos. Keyboard Used to type letters numbers and commands. Main input device Mouse It used to point , click and select items on the screen. Mix navigation easy. CPU The “brain” of the computer. Process data and continue operations. Printer Produces hard copy of documents and images. Webcam Used to capture photos and videos. Helpful for video calls. Speakers • Output device for sound. • Used to hear music, video etc. Scanner Converts physical documents into digital form. CONT............. Types Of Computer Based On Size And Purpose Size Super Computer Mainframe Computer Mini Computer Micro Computer 1. On basis of Size 1. Speed And Power Extremely fast, trillions of calculations per second. Use many processors working together 2. Large size and structure Very big machine, fills entire room. Looks like rows of cabinets with many connected parts. 3. Uses and working Solves complex problems like weather, space AI Works on many tasks at the same time (parallel processing) 4. Cost and requirements Very expensive and uses a lot of electricity. Needs special cooling systems and expert handling. 1 . Speed and power Medium processing power compared to mainframe computer Can support multiple users at the same time 2. Size and structure Smaller than mainframe computer Usually cabinet sized or rack - mounted 3. Uses and working Used in small businesses offices and labs. Handles moderate data and multi user tasks. 4. Cost and requirements Less expensive than mainframes. Needs basic cooling and maintenance. 1.Speed and power High processing power but less than supercomputers. Can handle many users at the same time. 2. Large size and structure Big machines, stored in special rooms Looks like large cabinets with connected systems 3 Uses and working Used in banks airlines and big organization Handle large data and supports multiple users together 4. Cost and requirements Expensive and needs continuous power Required cooling and professional maintenance Speed and power Low to moderate processing power Designed mainly for similar user Size and Structures Smaller in size desktop laptop tablet Compact and easy to use Cost and requirements Affordable and widely available Needs less power and minimal maintenance Uses and working Used for personal tasks like study, office, work etc. Runs basic applications and software 2. On basis of Purpose Purpose General Purpose Computer Special Purpose Computer General Purpose Computer Special Purpose Computer Multiple tasks High flexibility User controlled Eg : PC, Notebook, Smartphone Single tasks High flexibility Predefined controlled Eg : CT scan machine, thermometers , washing machines etc