CAIE IGCSE ICT Chapters 1–5: Computer Systems, Input/Output, Storage, Networks, and IT Effects

Comprehensive vocabulary flashcards covering CAIE IGCSE ICT Theory Chapters 1 through 5, including computer hardware and software, input and direct data entry devices, storage media and drives, network architectures and security, and the lifestyle and health effects of IT systems.

Hardware

All physical components or parts of a computer system that can be seen and touched, categorized into internal or external components.

Internal Hardware

Hardware components located inside the system unit, such as the motherboard, CPU, RAM, ROM, video card, sound card, HDD, and SSD.

Software

Coded instructions (programs) that control how the computer operates and processes data.

Application Software

Everyday programs used to perform specific user tasks, such as MS Word, MS Excel, video/audio editing software, and AutoCAD.

System Software

Programs that control computer hardware and enable smooth functioning, including operating systems, device drivers, linkers, compilers, disk cleaners, and anti-virus utilities.

Analogue Data

Physical data from the real world that changes continuously and smoothly from one value to another, such as temperature measurements.

Digital Data

Data represented by discrete or discontinuous values ($1$ and $0$), which is the only type of data understood and processed by computers.

Analogue to Digital Converter (ADC)

A hardware device used to convert continuous real-world analogue signals into discrete digital data ($1\text{s}$ and $0\text{s}$) for processing by a computer.

Central Processing Unit (CPU)

The brain of the computer consisting of an Arithmetic and Logic Unit (ALU) for calculations and logical decisions, a Control Unit to manage input/output devices, and registers for temporary data storage.

Random Access Memory (RAM)

Primary internal memory that temporarily holds data and instructions in use; it is volatile (contents are lost when power is turned off) and can be read from and written to.

Read Only Memory (ROM)

Primary internal non-volatile memory that permanently stores small, crucial data such as the BIOS and start-up/boot instructions, which can only be read from.

Manual Input Devices

Hardware devices requiring significant human physical effort to enter data into a computer, such as keyboards, mice, touchpads, and joysticks.

Direct Data Entry (DDE) Devices

Input devices that transfer data directly into a computer system with minimal human effort, such as barcode readers, RFID readers, and optical mark readers.

Tracker Ball Mouse

A pointing input device featuring a ball on top or on the side that stays stationary while navigating screens, designed to prevent or assist users with Repetitive Strain Injury (RSI).

Sensor

An input device that reads and inputs measurements of continuously changing physical quantities (e.g., temperature, pressure, light, moisture) into a computer, usually requiring an ADC.

Turbidity Sensor

A specialized sensor used in environmental monitoring to measure the clarity or cloudiness of water.

Magnetic Stripe Reader

A direct data entry device that reads encoded account or security details from the magnetic strip on the back of debit cards, credit cards, or keycards.

Contactless Debit Card Reader

A DDE device that wirelessly reads data off a card's embedded chip emitting radio waves, using a $128\text{-bit}$ encryption system for fast transactions at EFTPOS terminals.

Radio Frequency Identification (RFID) Reader

A DDE device that uses radio waves to capture data stored on a microchip tag via an antenna from several meters away without requiring line of sight.

Optical Mark Recognition (OMR)

A fast DDE technology that reads pencil or pen marks at specific predefined positions on paper forms, commonly used for scoring multiple-choice questionnaires and voting papers.

Optical Character Recognition (OCR)

A technology that scans hard copy text and uses specialized software to convert printed or written characters into editable electronic text files.

Quick Response (QR) Code

A two-dimensional matrix of dark and light squares capable of holding up to $4296\text{ characters}$ (compared to $30\text{ digits}$ in standard barcodes), used to access websites, applications, and product information.

Storage Medium

The actual physical hardware material upon which data is permanently stored, such as CD discs, DVD discs, and magnetic tape strips.

Storage Device

The hardware machinery used to read data from or write data to a storage medium, such as a CD/DVD drive or the read/write head of an HDD.

Serial (Sequential) Access

A data retrieval method where data must be read sequentially in the exact chronological order in which it was stored on the medium, as seen in magnetic tapes.

Direct (Random) Access

A data retrieval method where data is located and read immediately from a specific address on the storage medium without reading preceding records, as seen in HDDs, SSDs, and optical discs.

Magnetic Tape

A secondary storage medium made of a thin plastic strip coated in iron oxide, offering vast capacities up to $185\text{ TB}$ and sequential access, ideal for offline batch processing and enterprise archiving.

Hard Disk Drive (HDD)

A magnetic secondary storage device that uses mechanical actuators to move read/write heads over spinning platters to store operating systems, applications, and files via direct access.

CD-R and DVD-R

Recordable optical storage discs that can be written to only once using a red laser, after which the stored data becomes permanently read-only.

CD-RW and DVD-RW

Re-writable optical storage discs that can be written to, read, erased, and rewritten multiple times for backups and recording.

Blu-ray Disc

An optical disc that uses a blue laser to read and write data in smaller pits and lands, storing between $25\text{ GB}$ and $128\text{ GB}$ (up to five times more data than DVDs).

Solid-State Drive (SSD)

A non-volatile storage device that stores data as $1\text{s}$ and $0\text{s}$ by controlling electron flow within NAND logic gate chips, featuring access times of $0.1\text{ ms}$ with no moving parts.

SSD Endurance

A limitation of solid-state drives referring to the finite number of write and erase operations NAND flash memory can endure over time (typically around $3\text{ years}$ in high-write environments).

Cloud Storage

A remote data storage service where digital files are maintained and managed on remote servers accessible to clients over the internet.

Hybrid Cloud

A cloud computing infrastructure combining public and private cloud environments, storing sensitive private organizational data securely while keeping public data accessible.

Network

The wired or wireless interconnection of two or more computers to share hardware, software, files, and internet connections.

Network Interface Card (NIC)

A hardware component integrated into the motherboard that enables a computer to connect to a network by converting binary data into electrical signals.

Media Access Control (MAC) Address

A permanent $48\text{-bit}$ physical identifier assigned to a NIC, consisting of a manufacturer code followed by a device serial number.

Internet Protocol (IP) Address

A unique address assigned to a device by an ISP each time it connects to the internet to identify its network location, implemented as IPv4 ($32\text{ bits}$) or IPv6 ($132\text{ bits}$).

Data Packet Header

The initial section of a transmitted network packet containing the sender's IP address, receiver's IP address, packet sequence number, packet size, and total number of packets in the message.

Hub

A basic network hardware device that broadcasts incoming data packets to all connected ports on a LAN, causing unnecessary traffic and reduced bandwidth.

Switch

An intelligent network device that maintains a look-up table of device MAC addresses, directing incoming data packets strictly to the intended destination device.

Bridge

A network device with two ports used to connect two local area networks or LAN segments together that use the exact same communication protocol.

Router

A network device with multiple ports that joins LANs to the internet and routes data packets between different networks based on IP addresses using a routing table.

Bluetooth

A short-range wireless standard that uses radio frequencies to connect up to $8\text{ devices}$ in a WPAN over distances under $30\text{ m}$ at speeds up to $3\text{ MB/s}$.

Wi-Fi

A wireless networking technology that uses radio frequencies to connect multiple devices across ranges up to $100\text{ m}$ at data transfer rates up to $31\text{ MB/s}$.

Local Area Network (LAN)

A computer network covering a small geographical area (typically $10\text{ m}$ to $1000\text{ m}$), such as a single building, school, or office.

Wireless Local Area Network (WLAN)

A local area network that connects computers using radio or infrared signals through Access Points (APs) instead of physical cables.

Wide Area Network (WAN)

A network extending over large geographical distances ($100\text{ km}$ to over $1000\text{ km}$), connecting LANs via satellites and telephone systems; the internet is the largest example.

Hacking

The act of gaining unauthorized access to a computer system to steal, corrupt, alter, or delete private data.

Phishing

A social engineering attack where legitimate-looking emails containing malicious attachments or links are sent to deceive users into disclosing sensitive personal details.

Pharming

Malicious code installed on a user's computer or web server that automatically redirects the web browser to a fraudulent website without the user's knowledge.

Smishing

A fraudulent attack where fake text messages containing malicious links are sent to mobile phones to compromise personal data.

Spyware

Malicious software that operates secretly in the background to record user activity and monitor key presses on a keyboard to steal confidential data.

Biometrics

An authentication technique that grants system access by verifying an individual's unique biological features, such as fingerprint or facial scanning.

Physical Token

A tangible hardware authentication security object, either disconnected (requiring manual PIN entry) or connected, used to generate one-time access passwords.

Electronic Token

A software application installed on an authorized user's device that dynamically generates one-time verification codes for logging into secured networks.

Video Conferencing

Real-time communication between people at separate physical locations across a computer network using two-way interactive video and audio.

Web Conferencing

An online communication method using internet-connected computers that facilitates business meetings, interactive presentations, screen sharing, and slide exchanges.

Microprocessor-Controlled Devices

Labour-saving home devices containing microchips that perform automated tasks such as cooking, washing, and temperature regulation without requiring manual human effort.

Smart Motorways

Highways remotely monitored and controlled by a central computer system using automated variable signs and traffic lights to manage congestion and prevent accidents.

Automatic Number Plate Recognition (ANPR)

A camera-based tracking technology used on road networks to identify vehicles, detect traffic violations, and locate stolen cars.

LiDAR

Light Detection and Ranging technology that uses laser pulses to measure distances and build detailed $3\text{D}$ images of surroundings for autonomous train and vehicle navigation.

Repetitive Strain Injury (RSI)

A health condition causing pain in the wrists, fingers, and hands resulting from repetitive clicking of a mouse and continuous keyboard typing over long sessions.

Ozone Irritation

A health issue characterized by dry skin and respiratory irritation caused by ozone gas emissions from laser printers in unventilated rooms.