Computer Science Exam Study Flashcards

A comprehensive set of flashcards covering key computer science concepts and vocabulary.

Binary

A number system that uses only 0 and 1.

Denary / Decimal

The ordinary base-10 number system used by people.

Hexadecimal

A base-16 number system using digits 0–9 and letters A–F.

Bit

The smallest unit of data in a computer, representing either 0 or 1.

Byte

A group of 8 bits, often used to store one character.

Most significant bit (MSB)

The bit with the greatest place value in a binary number.

Least significant bit (LSB)

The bit with the smallest place value in a binary number.

Unsigned binary

A binary number format that represents only non-negative values.

Two’s complement

A method for representing negative integers in binary.

Sign bit

A bit used to indicate whether a number is positive or negative.

Overflow

Occurs when a calculation result is too large to fit into the available bits.

Fixed-point representation

A way of storing numbers with the binary point in a fixed position.

Fractional binary

Binary used to represent values after the binary point.

Floating-point representation

A method to store real numbers using a mantissa and an exponent.

Mantissa

The part of a floating-point number that stores significant digits.

Exponent

The part of a floating-point number that shifts the binary point.

Normalisation

Adjusting the mantissa for maximum precision.

Precision

The degree of detail stored in a number.

ASCII

A character encoding system assigning binary codes to letters, digits, and symbols.

Unicode

A larger character encoding standard for many languages and symbol systems.

Character set

A defined list of characters that a computer system can represent.

Security

Protection of computer systems and data against loss, damage, theft.

Physical security

Protection of hardware from physical threats like theft or fire.

Software security

Protection provided through software tools and settings.

Access control

Method of deciding who is allowed to use data or systems.

Authorisation

Process of deciding what an authenticated user can do.

Authentication

Proving that a user is who they claim to be.

Biometric security

Security using physical characteristics like fingerprints.

Encryption

Turning readable data into coded data.

Decryption

Converting encrypted data back into its original form.

Firewall

A security barrier monitoring traffic and blocking unauthorised access.

Antivirus

Software detecting and removing malicious software.

Malware

Software designed to harm or gain unauthorised access to systems.

Virus

Malware that attaches itself to a file and spreads when executed.

Worm

Malware that replicates itself and spreads across networks.

Trojan horse

Malicious software disguised as legitimate software.

Phishing

Tricking users into revealing sensitive data through fake methods.

Cracking

Gaining unauthorised access to a computer system.

Backup

A copy of data kept for restoration if original data is lost.

Disk mirroring

Storing the same data on two drives simultaneously.

Cloud storage risk

Problems arising from storing data on remote servers.

Validation

Checks if input data is sensible and in the correct format.

Verification

Confirms data has been copied or entered accurately.

Blockchain

A linked record of data blocks shared across a network.

Privacy policy

Statement explaining how user data is collected and used.

Unauthorised access

Access to data by a person without permission.

Ethics

Moral principles used to judge the rightness or wrongness of actions.

Ownership

Legal right to control and profit from digital work.

Copyright

Legal protection for the creator of original work.

Intellectual property

Creations of the mind, legally protected.

Plagiarism

Presenting someone else's work as your own.

Antiplagiarism check

A process used to detect copied content.

Open-source software

Software with publicly available source code.

Closed-source software

Software with source code not publicly available.

Licence

Legal agreement on how software may be used.

Digital rights management (DRM)

Technology used to control how digital content is used.

Privacy

Right to keep personal information from being exposed.

Data integrity

Accuracy and trustworthiness of data.

Cookies

Small files saved by websites on a user's device.

Legal image use

Using images legally according to copyright.

Dissemination of information

The sharing or spreading of information.

E-Gov service

A government service delivered electronically.

Software

Programs and instructions that direct computer operations.

System software

Software managing computer operation.

Application software

Software helping users perform specific tasks.

General-purpose software

Off-the-shelf software for common tasks.

Special-purpose software

Software designed for specific tasks.

Bespoke software

Software tailored to meet specific requirements.

Operating system (OS)

Main system software managing hardware and applications.

Utility software

Software maintaining or optimizing computer systems.

Device driver

Software allowing OS to communicate with hardware.

GUI (Graphical User Interface)

Interface allowing interaction using windows and icons.

CLI (Command Line Interface)

Interface requiring users to type commands.

Batch operating system

An OS processing jobs with little user interaction.

Network operating system

An OS supporting shared resources across a network.

Multi-user operating system

An OS allowing multiple users to access it.

Real-time operating system (RTOS)

An OS responding immediately to inputs.

CPU (Central Processing Unit)

The main processor controlling computer operations.

ALU (Arithmetic Logic Unit)

CPU component performing arithmetic and logic operations.

CU (Control Unit)

CPU component managing instruction execution.

Register

A fast storage location inside the CPU.

System bus

Group of buses connecting the CPU, memory, and components.

Data bus

Part of the bus carrying actual data.

Address bus

Bus carrying memory address to be accessed.

Control bus

Bus carrying control signals between components.

Fetch-decode-execute cycle

Process by which the CPU executes instructions.

Fetch

Stage of retrieving the next instruction from memory.

Decode

Stage of interpreting what the fetched instruction means.

Execute

Stage where the CPU performs the required action.

Clock speed

Rate at which the CPU performs cycles, measured in hertz.

Word length

Number of bits the CPU processes at once.

Pipelining

Technique overlapping different instruction stages.

RISC

Processor architecture emphasizing speed with simple instructions.

CISC

Processor architecture using complex instructions.

Von Neumann architecture

Design where instructions and data share the same memory.

RAM (Random Access Memory)

Main volatile memory storing currently used programs.

ROM (Read Only Memory)

Non-volatile memory storing permanent instructions.

Cache memory

Very fast memory storing frequently used data.

Virtual memory

Secondary storage used to extend RAM.

Swapping

Moving data between RAM and secondary storage.