A computer is an electronic device processing data (input) into information (output) using hardware (physical parts) and software (instructions). Computers vary by function, size, and power, broadly categorized as Analog, Digital, Hybrid, and within Digital, further classified into Microcomputers (desktops, laptops, tablets), Minicomputers, Mainframes, and Supercomputers, plus Workstations, Servers, and Wearables. Introduction to Computers Definition: An electronic machine that accepts data, processes it according to instructions, and produces useful information. Core Functions: Input, Process, Output, Store (IPOS). Components: Hardware: Physical parts (keyboard, mouse, monitor, CPU, memory). Software: Instructions/programs (OS, apps, games). Key Characteristics: Speed, Accuracy, Diligence (no fatigue), Versatility (multi-purpose). Types of Computers (Classification) A. By Data Processing Method Analog: Measures physical quantities (temperature, pressure); uses continuous data (e.g., old speedometers). Digital: Processes discrete data (0s and 1s); most common (PCs, smartphones). Hybrid: Combines Analog and Digital features (e.g., medical monitoring systems). B. By Size & Power (Digital Focus) Microcomputers: Small, personal use. Personal Computers (PCs): Desktops, Laptops, Tablets. Handhelds/Mobile Devices: Smartphones, PDAs. Minicomputers: Mid-range, shared processing (e.g., small business servers). Mainframes: Powerful, large-scale data processing (banks, airlines). Supercomputers: Extremely fast, complex calculations (weather forecasting, scientific research). C. By Purpose Servers: Provide services/resources to other computers (networks). Workstations: High-performance PCs for specialized tasks (engineering, design). Wearables: Fit on the body (smartwatches, fitness trackers).