IGCSE Computer Science Theory Notes

A set of flashcards covering key concepts from the IGCSE Computer Science Theory notes, including data representation, communication technologies, security, and file types.

What is the binary system based on?

The binary system is based on the number 2.

What does a byte consist of?

A byte is made up of 8 bits.

What is the denary value of 1 kilobyte (1 KB)?

1 kilobyte (1 KB) is equivalent to 1024 bytes.

What is the hexadecimal value of the denary number 10?

The hexadecimal value of the denary number 10 is A.

What is parity checking used for?

Parity checking is used to check whether data has been changed or corrupted following transmission.

What is the purpose of MIDI?

MIDI is used for the storage of music files and communication between electronic musical instruments.

What is the principle of a checksum?

Checksum is used to see if data has been transmitted correctly by comparing data blocks with an additional value.

Define lossy file compression.

Lossy file compression eliminates unnecessary bits of data and results in loss of original file quality.

What does HTTPS indicate?

HTTPS indicates that a secure connection is established using SSL encryption.

What is a MAC address?

A MAC address uniquely identifies a device on the internet and is part of the network interface card.

What type of data transmission is USB classified as?

USB is classified as asynchronous serial data transmission.

What is the difference between hacking and cracking?

Hacking is unauthorized access to a system to steal data; cracking involves modifying program code maliciously.

What does SSL stand for?

SSL stands for Secure Sockets Layer.

What are cookies used for in web browsing?

Cookies are used to track user preferences and behavior when visiting websites.

What is the function of a firewall?

A firewall filters information in and out of the computer to prevent unauthorized access.

What is the purpose of a proxy server?

A proxy server acts as an intermediary to filter internet traffic and keep the user's IP address private.

What is ASCII?

ASCII stands for American Standard Code for Information Interchange and represents characters as numeric values.

What is the main characteristic of RAM?

RAM is volatile memory that loses its contents when power is turned off.

How is data typically stored on a hard disk drive (HDD)?

Data is stored in a digital format on the magnetic surface of the disks (platters).

What is the role of an interpreter in programming?

An interpreter executes a high-level program statement by statement and does not produce an executable file.

Define phishing in terms of cybersecurity.

Phishing involves sending deceptive emails to trick users into providing personal data, like passwords or bank details.

What does the term 'digital signature' refer to?

A digital signature is a form of electronic authentication that ensures an electronic document is authentic.

What is transpiration?

Transpiration is the process by which plants release water vapor into the air from their leaves.

How does the sun influence the water cycle?

The sun provides the energy needed for evaporation and drives the water cycle.