29 of the Computer Science glossary’s terms, each with the part of the syllabus where you first meet it.
A logic gate whose output is 0 only when all of its inputs are 1, equivalent to an AND gate followed by a NOT gate.
The branch of AI that enables computers to analyse, understand and generate human language in text or speech.
A loop placed inside the body of another loop, so the inner loop runs through all of its passes for each pass of the outer loop.
A selection structure placed inside one of the blocks of another selection structure, so the inner condition is tested only when the outer branch has been taken.
A technique in which a router rewrites the private source IP address of each outgoing packet to its own public IP address, records the mapping in a translation table, and uses the table to send each reply back to the right private device.
The hardware component that connects a device to a network, converting data into signals for the transmission medium and receiving signals addressed to the device.
The bottom layer of the TCP/IP model, which moves data across a single physical link between two directly connected devices, using MAC addresses and turning frames into signals on the medium.
Any device attached to a network that can send, receive or forward data.
Dividing a network into smaller, separate parts, called segments, so that traffic between them can be limited and controlled.
The arrangement of the nodes in a network and the links that connect them.
A storage device, usually containing several drives, that connects to a local network so that many users and devices can store and share files on it.
In an artificial neural network, a processing unit that calculates a weighted sum of its inputs plus a bias and passes the result through an activation function to produce its output.
An invisible control character that marks the end of a line in a text file, written \n in Python and Java strings.
A firewall that, in addition to stateful inspection, examines the contents of packets to identify the application and user behind the traffic and to block known attack patterns.
A group of 4 bits, half a byte, which can represent 16 values and is written as one hexadecimal digit.
The result that no learning or optimisation algorithm performs best on every possible problem, so an algorithm's advantage on some problems is balanced by worse performance on others.
A single element of a linked structure, made up of a data field and one or more reference fields that point to other nodes.
Recursion in which each call of the subprogram makes at most one recursive call, so the calls form a single chain from the first call to the base case.
A requirement that states a quality or constraint the system must meet in the way it performs its functions, rather than a function it performs.
Data in a data warehouse that is not changed or deleted once loaded; users only read it, and new data is added in scheduled loads.
Memory that keeps its contents when the power supply is removed.
A logic gate whose output is 1 only when all of its inputs are 0, equivalent to an OR gate followed by a NOT gate.
Valid test data of the kind a program is expected to handle in everyday use, which it should accept and process correctly.
The process of organising the fields of a relational database into tables so that each fact is stored once, by removing repeating groups and unwanted dependencies according to a series of rules called normal forms.
Rescaling a feature to a fixed range, usually 0 to 1, using
A database that stores data in a non-relational model, such as key–value pairs, documents, wide rows or graphs, usually with a flexible schema and designed to scale across many servers.
A logic gate with one input whose output is the opposite of the input, 1 for an input of 0 and 0 for an input of 1.
The rule that ANDing a variable with 0 always gives 0, and ORing it with 1 always gives 1: and .
A special reference value, null in Java and None in Python, meaning that a variable does not refer to any object.