AQA A Level Computer Science Key Terms

AQA A Level Computer Science Key Terms with answers well explained 100% pass. Absolute Error - correct answersThe difference between the actual number and the nearest representable value. Abstract data type (ADT) - correct answersA data type whose properties are specified independently of any particular programming language. Abstraction - correct answersRepresentation that is arrived at by removing unnecessary details. Aggregation - correct answersRelationship between two object types in which one object type has a component which is of the other type. Ajax - correct answersWeb technology that allows only the part of a web page that needs updating to be fetched from the web server. Algorithm - correct answersA sequence of unambiguous instructions for solving a problem. It can be represented as a Turing machine program. Application programming interface (API) - correct answersA layer of software that allows application programs to call on the services of the operating system. Association - correct answersIf the relationship is not inheritance and it is not aggregation then it is an association. Asymptotic behaviour of f - correct answersIt is the behaviour of the function f(n) for very large values of n. Asynchronous serial data transmission - correct answersTransmission system in which the sender and receiver have separate clocks which are not kept synchronised. Instead, the clocks are synchronised temporarily at the start of a transmission. The arrival of data cannot be predicted by the receiver; s a start bit is used to signal the arrival of data and to synchronise the transmitter and receiver temporarily. Attribute - correct answersA property or characteristic of an entity (databases) or an object (OOP). Automation - correct answersTurning an abstraction into a form that can be processed by a computer. Backus-Naur Form, (BNF) - correct answersBackus-Naur Form, (BNF) Bandwidth - correct answersFor a transmission medium, the range of signal frequencies it may transmit. Base case - correct answersA value that has a solution which does not involve any reference to the general case solution. Baseband system - correct answersA system that uses a single data channel system in which the whole bandwidth of the transmission medium is dedicated to one data channel at a time. Basic operation - correct answersThe operation which contributes most to the total running time. Baud rate - correct answersThe rate at which signals on a wire may change. Behaviours - correct answersThe functions of the object or what the object does. Bit rate - correct answersThe number of bits transmitted per second Broadband - correct answersA multiple data channel system in which the bandwidth of the transmission medium carries several data streams at the same time. Bubble sort - correct answersA sorting algorithm where during a pass, neighbouring values are compared and swapped. Passes are made until no further swaps are needed. Cipher text - correct answersMessage data after it has been encrypted. Circular queue - correct answersWhen the array element with the largest possible index has been used, the next element to join the queue reuses the vacated location at the beginning of the array. Class definition - correct answersA template that can be used to create objects of that class. Client - correct answersA computer that uses the services provided by a server. Client-server system - correct answersA system in which some computers (the clients), request services provided by other computers, the servers.