OCR GCSE Computer Science (J277) Revision Flashcards

Flashcards covering key concepts from the OCR GCSE Computer Science (J277) Revision Guide.

What is the purpose of the CPU?

The CPU fetches, decodes, and executes instructions given by the user.

What does RAM stand for and what is its primary function?

RAM stands for Random Access Memory; it stores all the open programs and files for quick access by the CPU.

Define what ROM is.

ROM stands for Read Only Memory; it stores the BIOS and is non-volatile, meaning it retains data even when the power is off.

What is the difference between a LAN and a WAN?

A LAN (Local Area Network) covers a small geographical area, while a WAN (Wide Area Network) covers larger areas such as cities or countries.

What does the term 'clock speed' refer to in relation to CPU performance?

Clock speed measures how many instructions a CPU can execute per second, typically in Hertz.

What is the role of the ALU in the CPU?

The ALU (Arithmetic Logic Unit) performs all arithmetic operations and logical operations within the CPU.

What is a 'fetch-execute cycle'?

The fetch-execute cycle is the process through which the CPU retrieves an instruction from memory, decodes it, and executes it.

What are embedded systems?

Embedded systems are specialized computing systems designed to perform dedicated tasks within larger systems.

Name two components of the Von Neumann architecture.

MAR (Memory Address Register) and MDR (Memory Data Register).

What is cache memory and its purpose?

Cache memory is a small amount of high-speed memory located inside the CPU that stores frequently used data to speed up access.

How does the number of cores in a CPU affect performance?

More cores allow for multiple instructions to be processed simultaneously, increasing overall CPU performance.

Define 'network security'.

Network security involves measures taken to protect data during transfer and to safeguard the network against unauthorized access.

What is 'encryption' in network security?

Encryption is the process of converting data into a code to prevent unauthorized access during transmission.

What is the function of a router in a network?

A router directs data traffic between different networks, connecting them to the internet.

What are the key principles of the Data Protection Act 2018?

Data must be processed lawfully, for specified purposes, and must be kept secure, accurate, and only as long as necessary.

Define 'malware'.

Malware is malicious software designed to harm or exploit any programmable device or network.

What does 'SQL injection' mean?

SQL injection is a type of attack where malicious SQL code is inserted into a query to manipulate databases.

Why is multi-tasking important in an operating system?

Multi-tasking allows multiple applications to run simultaneously, improving user efficiency and system productivity.

Name one advantage of using solid-state drives over hard disk drives.

Solid-state drives have faster data access speeds than hard disk drives due to the absence of moving parts.

What is the significance of an IP address?

An IP address uniquely identifies a device on a network, allowing communication between devices.

How can users protect themselves against phishing attacks?

Users can protect themselves by being cautious of unsolicited communications and verifying the sources before providing personal information.