Components of Computer and Operating Systems
Computer Overview and Software Types
A computer is an electronic device that processes data to produce organized information as required by the user.
Software is an intangible, non-physical set of instructions or programs that enables execution of tasks.
System Software drives computer operations and manages internal functioning, such as an Operating System or Language Processor.
Application Software performs specific user tasks (e.g., Word Processor, Spreadsheet packages) and works under system software, using the Operating System as an interface to hardware resources.
Operating System and Booting
Operating System (OS) is a set of programs providing an interface to use computer resources efficiently, managing files, peripheral devices, and system startup.
Examples of Operating Systems include MS Windows, Unix, Linux, Apple Macintosh, ROS (Robot Operating System), and Mobile OS platforms such as Android and iOS.
Booting is the process of starting up a device and loading all necessary software to use it.
Hardware Components and Input Devices
Hardware refers to the electro-mechanical physical components of a computer, categorized into input devices, storage devices, CPU parts, and output devices.
Keyboard is a standard input device with buttons for alphabets, numbers, and special characters, typically containing to keys.
Keyboard styles include QWERTY, QWERTZ, AZERTY, and DVORAK, with QWERTY being the most common layout.
Mouse is a hand-held pointing device with two buttons and a scroll wheel to navigate contents on screen.
Joystick is a pointing device used mainly for video games; its pointer continues moving in the pointed direction until returned to its upright position.
Scanner converts hard-copy content into digital files (e.g., .pdf, .jpeg) by sensing reflected rays, categorized into Handheld scanner and Flatbed scanner.
Specialized Input Devices and Sensors
Optical Mark Reader (OMR) detects encircled dark black/blue marks on paper to evaluate answer sheets.
Magnetic Ink Character Reader (MICR) reads cheques using a nine (9) digit code printed in magnetic ink containing iron oxide.
Light Pen contains a light-sensitive detector to select or draw objects directly on a display screen.
Bar Code Reader projects a laser light beam onto vertical black lines of varying widths (bar codes) to translate bar patterns into numeric code inside the CPU.
Point of Sale (POS) machines enable retail payment transactions via debit cards, credit cards, or UPI.
Microphone captures voice audio, converting it into digital form for transmission or playback.
Web Camera (Webcam) captures real-time visuals for video links and video-conferencing stations.
Biometric Sensor captures unique physical details (such as fingerprints or iris patterns) to verify identity against a stored database.
Memory and Storage Devices
Memory represents the locations where the CPU receives, stores, and retrieves data and instructions.
Primary Memory (Main Memory) holds instructions and data required for active processing and internal computer management.
RAM temporarily holds information during active computer operation to allow instant access.