ict term 2 keywords

very long

analogue data

a continuous stream of data processed by humans

digital data

discrete data using only the values 0 and 1

logic gates

a very small component in a computer system that controls the flow of electricity

register

a small component in a computer system that temporarily stores data

denary

a base 10 number system using the number 0-9

Binary

base 2 number system using values 0 and 1

hexadecimal

a base 16 number system using the values 0-9 and characters A-F

MAC address

A unique address given to each computer at the manufacturing stage so that it can be used to identify the computer

Overflow Error

An error that occurs when a number larger than a register is generated

Character set

A set of characters containing the characters in the set and the binary values assigned to each character

Pixel

A small dot of color displayed with many other to create an image

Resolution

The dimensions of an image

Metadata

Additional data stored in an image which can provide information such as the dimensions of the image and the time the image was taken

Color depth

The amount of bits used to create each color in an image

Sound sampling

A little piece of sound recorded at regular time intervals

Sample rate

Amount of samples recorded per second

Sample resolution

The number of bits used to record each sample

Compression

A method using an algorithm to reduce the size of a file

Lossy

A method of compression that permanently removes data to reduce the size of a file

Lossless

A method of compression that temporarily alters data to reduce the size of a file

Perceptual music shaping

A process used in lossy compression that removes sounds that cant be heard by the human ear

Run length encoding (RLE)

An algorithm that groups together patterns and indexes them

Packets

A small unit of data

Packet header

A section of a data packet with contains information about the contents of the packet and the destination

IP Address

A unique address given to a device when it connects to a network

Payload

The actual data the sender is sending to the receiver

Trailer/footer

A section of the data packet that contains information about any error checking methods that could be used

Packet switching

A method of transmitting data packets across a network. Each packet is allowed to take its own route across the network.

Network

Computers of devices that are joined together using cables or wireless technology

Router

A network component that examines the data packet to obtain its destination address and then sends the packet to the address.

Serial

A transmission method that sends data one bit at a time down a single wire

Parellel

A transmission method that sends data multiple bits an a time down multiple wires

Interference

Disruption, such as electromagnetism, when data is being transmitted

Simplex

A transmission method that sends data in one direction only

Half duplex

A transmission method that sends data in both directions, but only one direction at a time

Full duplex

A transmission method that sends data in both directions and can be sent in both directions at the same times

USB (UniverSal serial bus)

An industry standard used to transmit data

USB Port

A socket in a device that allows you to insert a usb cable

USB Cable

A type of transmission media that uses the USB method to transmit data

USB Connection

A collective name used for when a USB cable is plugged into a usb port to transmit data from one device to another

USB Device

Name of the device that is plugged into the usb port in a computer

Ethernet

Another type of connection that can be used to transmit data within a network

Parity check

An error checking method that adds an extra bit to each byte to create an even of odd sum

Checksum

An error checking method that calculates data into checksum values. The checksum values are then compared after transmission to see if they match eachother.

Echocheck

An error checking method that sends a copy of the transmitted data back to the sender to compare with the original data sent.

Automatic repeat request

An error checking method that uses acknowledgement and timeout to make sure the data has been sent correctly.

Acknowledgement

A message sent by one device to another to indicate whether the data has been sent correctly

Timeout

a period of time set and used to wait for an acknowledgement to be received

Check digit

An error checking method for data entries. A calculation is performed on the data entered to create a value. Checkdigit values are then compared to see if the data entered is correct

Encryption

A method for securing data for storage of transmission that scrambles the data and makes it meaningless

Plain text

The name given to the data before encryption

Cipher text

The name given to the data after transmission

Symmetric encryption

A method of encryption that uses the same keys to encrypt and decrypt the data

asymmetric encryption

A method of encryption that uses two different keys (public and private) to encrypt and decrypt

internet of things

the connection of computer systems and everyday devices using the internet to exchange data

control processing unit (CPU)

A component in a computer system that processes data and instructions

Microprocessor

An integrated circuit that can perform many of the functions of a CPU

embedded system

a system designed to perform one function

Fetch decode execute cycle

a cycle where data and instructions are processed

architecture

the design of a computer system including the components it contains

Input device

A device which allows data to be entered into a computer system

Random Access Memory (RAM)

A component in a CPU that holds data and programs currently in use

Hard drive

A storage device that stores data permanently until deleted by the user

Program counter (PC)

A component in the CPU that stores the address of the next instruction to be processed

Memory address register (MAR)

A component in the CPU that holds the address of the instruction located in the RAM

Address bus

Wires used to transmit addresses between the components in a computer system

Memory data register (MDR)

A component in the CPU that stores the data or instruction fetched from a RAM

Data bus

Wires used to transmit data between components in a computer system

Current instruction register (CIR)

A register built in the control unit (CU) that holds the instruction currently being processed by the CPU

Control unit (CU)

A component in a computer system that controls all the operations in a CPU

Instruction set

a set of commands that can be processed by the CPU

Arithmetic logic unit (ALU)

A component in the CPU that performs all the mathematical and logical operations that are needed when processing data and instructions

Accumulator (ACC)

A component built into the ALU that stores the result after an interim calculation

Control bus

Wires used for the transmission of control signals between components in the computer system

Core

Part of a computer that contains all the components used in the fetch decode execute cycle.

Clock speed

Number of fetch decode execute cycles that can be completed in one second

Cache

A type of storage space built into a CPU to store the most used instructions and data

Output device

A device that can be used to obtain the result of data that has been processed

Sensor

Type of input device that is used to capture the data from its immediate environment

Automated system

A system designed to operate without the need for any human intervention

Primary storage

A type of storage that is directly accessed by the CPU

Secondary storage

A type of storage that stores data permanently until it is deleted by the user

Read only memory (ROM)

A type of primary storage that stores the start up instructions of a computer

Magnetic storage

A type of secondary storage that stores data using the properties of magnetism

Optical storage

A type of secondary storage that stores data using lasers

Solid state storage

A type of secondary storage that uses transistors to store data

Semiconductor chips

An electrical circuit, where transistors are sat on semiconductor material such as silicon

Cells

The intersection of the rows and columns of the transistors in solid state storage

Transistors

A device that acts as a switch or a gate to electrical signals

Control gates

A transistor that controls the flow of electric current

Floating gate

A transistor that can store electrical charge

Virtual memory

Memory that can be used as an extension to RAM

Page

A unit of data

Cloud storage

Storage owned by a third party, users can access it using the internet

Servers

A component that acts as a central resource for the storage of data and applications of for providing a service

Network

Computers and devices that are joined together using cables or wireless technology

Network interface card (NIC)

A component in a computer that allows it to connect to a network

Transmission media

Cables used to transfer data in a network

Media access control (MAC) address

[for NIC]

A unique address given to a NIC by a manufacturer

Data packet

A unit of data used to transmit data across a network