NIELIT ECC key terms

Processed or organised data that has meaning and can support decisions. In computing it is distinguished from raw data, which is unprocessed facts and figures.

Raw, unprocessed facts, numbers, or symbols stored or transmitted by a system. On its own it lacks context; processing converts it into useful information.

Information and Communication Technology: the combined use of computing hardware, software, networks, and telecommunication to store, process, and exchange information.

An electronic machine that accepts input, processes it under stored program control, produces output, and can store results. Its core parts are CPU, memory, and input/output units.

Central Processing Unit: the part of a computer that fetches, decodes, and executes instructions. It contains the arithmetic logic unit, control unit, and registers.

A very small, very fast storage location inside the CPU used to hold an instruction, an address, or an operand during processing. Registers are faster than cache memory.

A small high-speed memory placed between the CPU and main memory that holds recently used data and instructions to reduce average access time.

Random Access Memory: volatile read/write main memory holding programs and data currently in use. Its contents are lost when power is switched off.

Read Only Memory: non-volatile memory whose contents are normally written during manufacture and retained without power. It often stores firmware such as the boot program.

Software permanently stored in read-only or flash memory that controls hardware at a low level, for example the BIOS or a device controller program.

System software that manages hardware resources, files, memory, and processes, and provides services to application programs through a user interface and system calls.

A program that translates an entire source program written in a high-level language into machine code or object code before execution, reporting syntax errors during translation.

A program that translates and executes source code one statement at a time, without producing a separate object file. It is slower to run but easier to debug.

A translator that converts assembly language, which uses mnemonics for machine instructions, into the corresponding machine code object program.

A finite, ordered set of unambiguous steps that solves a problem or performs a computation, with defined input and output. It is independent of any programming language.

A diagram using standard symbols such as rectangles, diamonds, and parallelograms connected by arrows to show the sequence of steps in an algorithm or process.

A structured, informal language mixing plain words and programming constructs to describe an algorithm. It is readable by humans and not tied to a specific syntax.

An organised collection of related data stored so that it can be easily accessed, managed, and updated, usually under the control of a database management system.

Database Management System: software that defines, stores, retrieves, and secures data in a database, and controls concurrent access by multiple users.

A column or set of columns whose values uniquely identify each row in a database table. It cannot contain duplicate or null values.

A positional number system with base 2 that uses only the digits 0 and 1. Each position represents a power of two, which suits digital circuits.

A base-16 number system using digits 0-9 and letters A-F. It is widely used as a compact way to write long binary values such as memory addresses.

American Standard Code for Information Interchange: a 7-bit character code assigning numeric values 0-127 to letters, digits, punctuation, and control characters.

A universal character encoding standard that assigns a unique code point to characters of most of the world's scripts, supporting far more symbols than ASCII.

A basic digital circuit that performs a Boolean operation such as AND, OR, NOT, NAND, or NOR on one or more binary inputs to produce a single output.

A branch of mathematics using variables with values 0 and 1 and operators AND, OR, and NOT. It is used to analyse and simplify digital logic circuits.

A bistable digital circuit that stores one bit of state and can hold it until changed by a clock or input. It is the basic building block of registers and memory.

A material such as silicon or germanium whose conductivity lies between that of a conductor and an insulator, and which can be controlled by doping and applied voltage.

A two-terminal semiconductor device that conducts current mainly in one direction. It is used for rectification, protection, and voltage regulation in electronic circuits.

A three-terminal semiconductor device used to amplify or switch electronic signals. In digital circuits it acts as the controlled switch inside logic gates.

The process of varying a property of a carrier wave, such as amplitude, frequency, or phase, in accordance with a message signal so it can be transmitted efficiently.

A modulation technique in which the amplitude of a high-frequency carrier is varied in proportion to the message signal while its frequency and phase stay constant.

A modulation technique in which the instantaneous frequency of a carrier is varied according to the message signal, giving better immunity to amplitude noise.

The recovery of the original message signal from a received modulated carrier. It is the reverse of modulation and is performed by a detector or demodulator circuit.

The range of frequencies a channel or signal occupies, usually the difference between its upper and lower limits. It determines how much data can be carried.

A unique numeric label assigned to a device on an IP network for identification and routing. IPv4 uses 32 bits, while IPv6 uses 128 bits.

A 32-bit value that separates the network portion of an IPv4 address from the host portion, allowing devices to decide whether a destination is local.

A network device that forwards packets between different networks by examining destination IP addresses and choosing the best path from its routing table.

A network device that connects devices within a local area network and forwards frames to the correct port using learned MAC addresses.

A 48-bit hardware address burned into a network interface card, used at the data link layer to identify a device on a local network.