Glossary of terms
A
Algorithm – A sequence of logical instructions for carrying out a task. In
computing, algorithms are needed to design computer programs.
API (Application programming interface) – A software library interface used
to share data between software and, in particular, web applications.
App – abbreviation for ‘application’
Application – A software program that allows a user to perform a specific
task.
Application server – software that handles scripting and programming on the
server for a website.
Assignment – Setting a value of a variable in a computer program.
Argument – A value that is acted on in a computer program function.
Array – A set of data values of the same type, stored in a sequence in a
computer program.
ASCII (American Standards Code for Information Interchange) – A 7-bit
character set used for representing English keyboard characters. ASCII can
encode up to 128 characters.
Assembly language – A family of low level programming languages.
Attribute – The characteristics of an entity. In databases, attributes are
represented in fields, e.g. attributes of a film could be the actors, director and
duration.
B
Bandwidth – Bandwidth measures the amount of data that can transfer
through a communications channel over a given period of time.
Base 16 – A number system using 16 characters from 0-9 and A to F, also
known as Hexadecimal or Hex
Binary – A number system that contains two digits, 0 and 1. Also known as
base 2.
Binary digit or Bit – The smallest unit of data in computing represented by 1
or 0 in binary.
Bitmaps – An image made up of pixels. This type of image loses quality if its
width and/or height are increased.
Bitrate – In computing, the number of bits process per second
Boolean – A data type in computing which only has two possible values, true
or false.
Bootstrap Loader – a program that resides in the computer's EPROM, ROM,
or other non-volatile memory. It is automatically executed by the processor
when turning on the computer. The bootstrap loader reads the hard
drives boot sector to continue the process of loading the computers operating
system.
Browser – An application used to view web pages, e.g. internet Explorer or
Google Chrome.
Bug – An error in a program that causes it to fail.
Bus – The wires through which data travels from one part of a computer to
another on the motherboard.
BYTE - Collection of Bits, A unit of data containing 8 bits.
C
Cache Memory – A piece of temporary memory. It can refer to a part of the
RAM, storage disk, CPU, or an area for storing web pages.
CAD (computer-aided design) – The use of computers to assist in any of the
phases of product design.
CD Drive – Short for Compact Disk-Recordable drive, a type of disk drive that
can create CD-ROMs and audio CDs. This allows users to "master" a CD-ROM or
audio CD for publishing.
Chip – An electronic circuit that computer systems are made from.
Class – In computing, a class is a category of objects in object orientated
programming.
Client – The computer on a network that requests data from a server.
Client-server – A form of computer networking where the website or web
application is hosted on a server and accessed by client computers.
Clock Speed – The speed of a computer CPU, measured in hertz.
Cloud based storage – A term often used to descried a location on the
internet from which software applications are run and where data is stored.
Code - Computer code is a set of rules or instructions. It is made up of words
and numbers and when you put them in the right order it will tell your
computer what you want it to do. You can program lots of things with code.
Colossus – The first programmable electronic computer, used in Britain
during World War 2
Compression – A method of reducing file sizes, particularly in digital media
such as photos, audio and video.
Constant – A value in a computer programming that does not change.
Control Flow – This refers to the order in which actions are carried out in a
process. This is often illustrated using flow charts.
Core – A processing unit within a CPU, CPUs can have multiple cores.
Corrupt – A computer file that is damaged, possibly unusable.
CPU – Central Processing Unit – The brains of the computer that processes
program instructions. Also called a microprocessor.
CSS (cascading style sheet) – Used to format the style of a web page.
D
Data – Units of information. In computing there can be different data types
including integers, characters, and Boolean. Data is often acted on by
instructions.
Data packets – A piece of data sent over a network. Messages have to be
broken down into binary data packets before they are transferred.
Data Structure – The way that data is stored in a database or program.
Data type – In computer programming, data is divided up and organised
according to type, e.g. numbers, characters and Boolean.
Database – A system designed to store data in an organised way, making it
easier to search for the information you need.
DBMS – Database management system – system that provides an organised
tool for managing data.
Debug – The process of finding and correcting programming errors.
Decimal – Another name for the number system know as base 10. Decimal uses
characters 0-9.
Denary – The number system most commonly used by people. It contains 10
unique 0-9. Also known as decimal and base 10.
DVD Drive - A DVD drive is a component of a computer or other electronic
device designed specifically to utilize digital versatile discs, or DVDs.
E
Encryption – Files that are encrypted have been altered using a secret code
and are unreadable to unauthorised parties.
End user – The person who uses the final product.
Ethernet – A copper cable used to connect computers to a network.
Execute – The run a computer program.
F
Field – An element of a database record in which one piece of information is
stored. For example ‘name’ in an electronic address book.
Firmware – The software that has been written onto a hardware device.
Flash Memory – A form of memory in a computer that uses electronic
transistors to store data.
Flat-file database – A database consisting of only one table often stored as a
comma separated values file.
Floating Point – A data value in computer programming used to denote
decimal numbers.
Foreign key – A reference to a primary key in a relationship database table.
Forms - In a database context, a form is a window or screen that contains
numerous fields, or spaces to enter data. Each field holds a field label so that
any user who views the form gets an idea of its contents. A form is more user
friendly than generating queries to create tables and insert data into fields.
For Loop – A method used in programming to repeat a set of instruction for a
set amount of times.
Front-end – The part of an application seen and used by the end user.
FTP (Flie Transfer Protocol) – a protocol used to transfer large files across
the internet
Function – A type of procedure in programming. It is a section of code that
performs a specific task, it can be named and reused in different parts of the
program.
G
GIF (Graphics interchange format) – an 8-bit digital image format which
uses lossless compression. Also used for short animations.
Gigabyte - gigabyte is 1000000000bytes. The unit symbol for the gigabyte
is GB.
Gigahertz gHz – one billion hertz per second = one gigahertz. This is a
measure of frequency and is used to describe bus speeds and CPU clock speeds.
GPU (Graphical processing unit) – A computer chip dedicated to processing
graphics.
H
Hard Drive – A device used to store vast amounts of data
Hardware – The physical parts of a computer system, e.g. a graphics card,
hard disk drive, CD drive, etc.
Heat Sink Sensor – A component used on computer motherboards to cool the
CPU
Hertz – The unit of frequency, symbol ‘Hz’. 1 Hz is 1 wave or cycle per second.
HTML (Hypertext Markup Language) – The language used to write and
display web page documents.
HTTP (Hypertext transfer protocol) – A request/response standard. Web
browsers sends requests and websites or servers and respond to requests.
I
Index – A data structure in a database that groups a set of records associated
with a keyword.
Information – information is data that is accurate, specify and organised for a
purpose. Presented in context, information is data with a meaning.
Integer – A whole number – in computing, a data type which represents
signed (positive) or unsigned (negative) whole numbers.
Internet – A global network connecting millions of computers.
Interpreter – A program that translate high level programming languages in
machine code. Programs can either be interpreted or compiled.
IP address – A unique address for each computer device on a network.
IP (Internet Protocol) – A set of rules for communicating over the internet. IP
can also stand for intellectual property.
Iteration – In computer programming, this is a single pass through a set of
instructions.
J
JavaScript – An interpreted programming, or scripting, language used to make
dynamic elements in web applications.
JPEG (Joint Photographic Experts Group) - a digital image format which uses
lossy compression.
K
1. Kilobyte - a unit of memory or data equal to 1,024 bytes.
L
Linux – An operating system, similar to Windows or Mac OS. Linux is free and
open-source, meaning anyone can improve it and share their improvements.
Logic gate – Circuit components which take several inputs, compare the inputs
with each other, and provide a single output based on logical functions such as
AND, OR and Not.
Loop – A method used in programming to repeat a set of instructions
Lossless – A form of compression that encodes digital files without losing
detail. Files can be also stored to their uncompressed quality.
M
Magnetic storage - Magnetic storage media and devices store data in the
form of tiny magnetised dots. These dots are created, read and erased using
magnetic fields created by very tiny electromagnets.
Mark-up Language – A language used to present and organise text, especially
within a HTML document.
Megabyte (MB) – a measurement of file size or storage capacity. 1,048,576
bytes.
Memory – The part of a computer that stores data.
Memory Location – In computing, this is an address in the primary memory
where data values are stored.
Method – In computing, a method is a procedure that is executed in an object
orientated programming language.
Methodologies - A system of broad principles or rules which are followed in
order to solve different problems within computer science. Unlike
an algorithm, a methodology is not a formula but a set of practices.
Module – A small component of computer program that may contain several
routines.
Motherboard – The circuit board inside a computer that houses the CPU,
memory and connections to other devices.
MySQL – Open source database management system.
N
Network – A group of interconnected computers
Network Card – A piece of hardware that connects a computer to a network.
Nibble – half a byte, containing 4 bits
Non-Volatile memory – A form of computer memory that stores data even
when not powered.
NoSQL – a form of non-relational database.
O
Object orientated programming - Object-oriented programming (OOP) is
a programming language model organised around objects rather than "actions"
and data rather than logic.
Octal - The octal numeral system, or oct for short, is the base-8 number
system, and uses the digits 0 to 7. Octal numerals can be made from binary
numerals by grouping consecutive binary digits into groups of three (starting
from the right)
Open Source – A model for creating technology that promotes free access to
its design and makes it free to share
Optical storage - Optical storage is the storage of data on
an optically readable medium. Data is recorded by making marks in a pattern
that can be read back with the aid of light, usually a beam of laser light
precisely focused on a spinning disc.
OS – Operating System – The software that runs a computer
OSX – A version od Apple’s Mac OS operating system for Apple computers.
P
Parameter – in computer programming, a parameter in a variable passed in to
a function or procedure.
Peripheral hardware – A piece of hardware that connects to a computer, e.g.
a mouse, keyboard, printer or scanner.
PHP – A server-side programming language used in web development.
Pixel – One of the individual units (often called dots) that make up an image.
PNG (portable network graphics) - a digital image format that uses lossless
compression.
Primary key – The unique identifying value for records in a database.
Procedure – A section of computer code that performs a specific task.
Program – Sequences of instructions for a computer.
Programming language – A language used by a programmer to write a piece
of software. There are many programming languages.
Pseudocode – A method of writing up a set of instructions for a computer
program using plain English. This is a good way of planning a program before
coding.
Python – A high-level programming language
Q
Query Language – A type of programming languages used to work with
databases. A typical example is SQL.
Queries – A search or question performed inside a database.
R
RAM – Random access Memory – memory that is constantly being written
to and read from. It does not retain its contents without a constant supply of
power, i.e. when a computer is turned off, everything stored in its RAM is lost.
Raspberry Pi – A low budget, pocket sized computer which is easy to
program.
Record – All of the data relating to one entity in a database.
Relational database – A database compromising of multiple tables joined
together through a common link.
Resolution – The fineness of detail that can be seen in an image – the higher
the resolution of an image, the more detail it holds. It is measures in dots per
inch (dpi).
RPM (revolutions per minute) – a measure of speed of rotation.
ROM (Read Only Memory) - ROM retains its contents even when the
computer is turned off. ROM is referred to as being nonvolatile
Run – To execute a program.
S
Semantic Error – An error in the logic of a computer program producing
unexpected results.
Selection – A decision within a computer program when the program decides
to move on based on the results of an event.
Server – A computer that holds data to be shared with other computers. A web
server stores and shares websites. Servers require server software.
Software – The programs, application and data in a computer system. Any
part of a computer system that aren’t physical.
Software development cycle – a method for planning how to create and
maintain a system such as a computer program.
Standard – A guideline or specification which is widely agreed and commonly
accepted, but do not necessarily have the force of law.
Statement – The smallest element of a programming language which
expresses an action to be carried out.
String – A sequence of characters often stored as a variable in a computer
program.
Storage – The hardware of a computer that stores data long term, such as a
memory card or hard drive.
SSD (Solid State Drive) - a nonvolatile storage device that stores persistent
data on solid-state flash memory
SQL (Structured query language) – A programming language used to
control databases.
System – Refers to the inputs, stores, flows and outputs of water into a glacier
T
Table – Contain all the fields and records for one particular collection of
entities in a database.
Terabyte – A measurement of file size or storage capacity, 1000 gigabytes.
Terminator – A device that terminates signals to prevent them reflecting back
down the line.
Testing – An important part of computer programming which involves
checking a program for errors.
Truth Table – Used to assess possible results of a Boolean algebra statement.
Types of relationships within a database Many to many - When one or more rows in a table
are associated with one or more rows in another
table. An example of a many-to-many relationship is
a table of customers who can purchase many
different products and a table of products that can
be purchased by many different customers.
One to many - A row in a table in a database can
be associated with one or (likely) more rows in
another table. An example of a one-to-many
relationship is a single order has many items on that
order.
One to one - A row in a table is associated to one
and only one row in another table. An example of a
one-to-one relationship is a person can have one
social security number and a social security number
can only be assigned to one person.
U
URL (Uniform Resource Locator) – Each web page address on a network is
written as a URL. It contains the IP address and the Domain Name Servers and
web page Details.
USB (Universal serial bus) – connects peripheral devices to a computer, eg a
camera, memory stick, keyboard, mouse or mobile.
USB Memory Stick – A physically small storage device. It normally plugs into a
USB port. They are also called USB sticks, memory sticks, thumb or flash drives.
These devices use solid state memory with no moving parts.
V
Variable – In a computer program, this is a memory location where values are
stored.
Vector – an image stored as mathematical instructions for how to draw it this
mean its width and height can be increased without the loss of quality.
Virus – Computer code design to damage a computer system
Virtual Memory – a section of a computer storage drive which is temporarily
used as RAM.
Volatile memory – A section of a computer storage drive which is
temporarily used as RAM.
VPN (virtual private network)- A private network that can be accessed
securely through a public network such as the internet.
W
Web-based applications – An application that runs within a web browser.
Web Browser – An application that displays web pages.
Web Server – the location for storing the contents of a website.
Windows – Microsoft’s brand of operating systems, e.g. Windows 98, Windows
XP, Windows Vista, Windows 7, Windows 8 and Windows 10.
Wireless – A connection that does not need wires and transmits data through
radio signals.