Sri Lanka ICT Service Exam key terms

The main processor chip that fetches, decodes and executes program instructions, performing arithmetic, logic and control operations. Its speed is measured in clock cycles per second (GHz) and core count.

Volatile working memory that holds programs and data currently in use so the processor can reach them quickly. Its contents are lost when power is removed, unlike storage drives.

A small, very fast memory block inside or near the processor that stores recently used instructions and data to reduce waiting time on slower main memory.

A technique where the operating system uses part of secondary storage as an extension of RAM, swapping pages in and out so programs larger than physical memory can run.

The main printed circuit board of a computer that connects the processor, memory, storage, expansion slots and input/output ports, and carries the buses between them.

Any hardware attached to and controlled by a computer to add function, such as a keyboard, printer, scanner or external drive. Peripherals may be input, output or storage devices.

System software that manages hardware resources, schedules processes, controls files and provides services so application programs can run without addressing hardware directly.

The core part of an operating system that stays resident in memory and handles privileged tasks such as process scheduling, memory management and device control.

Software that translates general operating system commands into the specific signals a particular hardware device understands, allowing the OS to support many device models.

A memory management method that divides memory into fixed-size blocks called pages and frames, letting the operating system load only needed pages and move unused ones to disk.

A numeric label assigned to a device on a network so data packets can be routed to it. IPv4 uses 32 bits; IPv6 uses 128 bits to overcome address exhaustion.

A 32-bit pattern that identifies which part of an IPv4 address names the network and which part names the host, enabling division of a network into smaller segments.

A hierarchical distributed naming service that translates human-readable domain names into IP addresses so users need not remember numeric addresses.

A network covering a limited area such as an office or building, where connected devices share resources at high speed under a single administrative control.

A network device that forwards data packets between different networks, choosing the best path using routing tables, and typically connecting a LAN to the internet.

Software that stores, retrieves and controls access to data in a database, enforcing structure, integrity rules and concurrent access for multiple users.

A column or combination of columns whose value uniquely identifies each row in a table; it cannot be null and no two rows may share the same value.

A column in one table that references the primary key of another table, enforcing referential integrity so records cannot point to nonexistent parent records.

The process of organizing relational tables to reduce duplicated data and update anomalies by splitting information into related tables according to successive normal forms.

A structured sequence of phases for building information systems, typically planning, analysis, design, implementation, testing, deployment and maintenance, each producing defined deliverables.

An iterative approach that delivers working software in short increments, welcomes changing requirements and relies on close collaboration between developers and users.

A document stating what a system must do and the constraints it must satisfy, written clearly enough to guide design, contracting and later acceptance testing.

Formal testing by intended users against agreed business requirements to confirm a system is fit for purpose before the client formally accepts and pays for it.

The transformation of readable data into ciphertext using a key so that only parties holding the correct key can reverse it and read the original content.

Access control requiring two or more independent kinds of evidence, such as a password plus a one-time code from a token or phone, so a stolen password alone is insufficient.

A social engineering attack that sends deceptive messages imitating a trusted party to trick recipients into revealing passwords, payment details or installing malware.

Any software written to harm or gain unauthorised access to a system, including viruses, worms, trojans, ransomware and spyware. It spreads through files, links and vulnerable services.

A hardware or software filter placed between networks that permits or blocks traffic according to defined rules, protecting internal systems from unwanted external connections.

A one-way mathematical routine that converts data of any length into a fixed-length digest; even a tiny change to the input produces a completely different digest.

An electronically signed statement from a trusted certificate authority binding a public key to an identified owner, used to prove identity in secure web and email transactions.

The delivery of government information and services to citizens, businesses and agencies through internet and digital channels, aiming for convenience, transparency and efficiency.

The ability of different systems and agencies to exchange data and use it meaningfully, usually achieved through shared standards, data formats and interfaces.

The gap between people who have affordable access to digital devices, connectivity and skills and those who do not, often following income, age, disability and regional lines.

A defined set of rules and endpoints that lets one software system request data or actions from another without knowing its internal implementation.

An architecture that builds an application as small independent services communicating over networks, each deployable and scalable separately, in contrast to one large monolithic program.

Provision of computing resources such as servers, storage and software over a network on demand, billed by usage and managed by the provider rather than the user.

The principle that data is subject to the laws and governance of the country where it is stored or generated, which affects where governments may place systems and backups.

Legal and organisational rules governing how organisations may collect, use, store and disclose information about identifiable individuals, including consent and breach notification duties.

A contract clause or document defining measurable service expectations such as uptime, response time, support hours and remedies when targets are missed.

The full lifetime cost of an ICT investment, covering purchase, licences, integration, training, support, upgrades and disposal, not just the initial price.

The formal process by which a public body identifies a need, specifies requirements, invites bids, evaluates them against published criteria and awards a contract.

The deep redesign of processes, services and culture around digital technology, changing how work is done rather than merely replacing paper with computers.