Unit 1 Gloss orig

Question 1

application service provider (ASP)

Answer 1

An organisation offering access to application software run on centralised servers and accessed over the internet using a browser or specialised client software

Question 2

application software

Answer 2

Software designed to carry out a function for the user, e.g. a payroll application or a word processing program (as opposed to systems software like the operating system or middleware).

Question 3

bandwidth

Answer 3

The data transfer capacity of a communications link, usually measured for digital communications in units of bits per second

Question 4

central processing unit (CPU) / processor

Answer 4

The part of a computer system that carries out the instructions of a software program in order to process data

Question 5

centralised computer system

Answer 5

A computer system where all, or almost all, of the processing is carried out at one central location

Question 6

computer bureau

Answer 6

The clients of a computer bureau pay for the computer time needed to run their business software on the bureau’s computers – a similar approach to current application service providers, however this idea predates the internet so data transfer was via magnetic disks or tapes.

Question 7

concurrent system

Answer 7

A system which may have a number of activities active at the same time and allows all of its active activities to make progress

Question 8

deadlock

Answer 8

A state of a concurrent system where the whole system stops because two or more components are waiting for each other to continue (and they never do).

Question 9

distributed system

Answer 9

A system containing a number of distinct components at different locations, where each component is, in some sense, a computer system itself and the components are linked by a network. The system may demonstrate transparency to varying degrees.

Question 10

dumb terminal

Answer 10

A computer terminal with very little local processing power – simply a screen and keyboard together with some simple communications links

Question 11

embedded system

Answer 11

A computer system that is physically partofa larger system (often a real-time system) and may monitor or control the system of which it forms a part

Question 12

enterprise

Answer 12

A large organisation, such as an industrial company, a bank or a government department.

Question 13

enterprise software

Answer 13

Software that runs on enterprise systems.

Question 14

enterprise system

Answer 14

A computing system suitable for the requirements of an enterprise

Question 15

fault-tolerant system

Answer 15

A system that can continue normally (or perhaps with reduced functionality) after a hardware or software error has occurred.

Question 16

grid computing

Answer 16

A way of harnessing the power of many computers distributed across the internet to solve problems requiring great processing power.

Question 17

host / node

Answer 17

An individual component of a distributed system that has some processing capability.

Question 18

interoperability

Answer 18

The ability of systems to work across a variety of different environments or platforms.

Question 19

local area network (LAN)

Answer 19

A computer network where all the hosts are physically close together, often in the same building, and normally entirely controlled by one organisation or department (in contrast to a WAN).

Question 20

location-aware system

Answer 20

A mobile system that can take advantage of satellite location services (such as GPS) to determine its location and hence adapt its behaviour depending on its physical location.

Question 21

memory

Answer 21

Short-term, rapidly accessed computer hardware for storing data – often, but not always, volatile (loses data if powered off), e.g. RAM.

Question 22

mobile system

Answer 22

A distributed computer system some of whose components are not fixed in their location, e.g. a mobile phone network

Question 23

monolithic architecture

Answer 23

A design of computer system in which all, or almost all, the processing is carried out at one central location, e.g. a mainframe computer.

Question 24

multi-core

Answer 24

A design of CPU chip with more than one processing unit (or ‘execution core’) that can improve performance by operating in parallel – the special case of two processing units is called dual-core

Question 25

multiprocessor

Answer 25

A computer system with morethan one CPU – this could mean anything from two CPUs to thousands of CPUs

Question 26

operating system

Answer 26

Software that interacts with the underlying hardware of a computer system and provides a layer or platform on which other software, such as application software, can run without needing detailed knowledge of the hardware.

Question 27

parallel bus

Answer 27

A set of parallel wiring connections that can link closely positioned CPUs in a multiprocessor system

Question 28

parallel system

Answer 28

A concurrent system that can really carry out a number of activities simultaneously because it has more than one processor.

Question 29

personal digital assistant (PDA)

Answer 29

A small handheld computing device, usually with relatively limited resources of display, memory and storage.

Question 30

pseudo-parallel system

Answer 30

A concurrent system which shares processor time between a number of activities but only one activity is actually running at any given time

Question 31

random access memory (RAM)

Answer 31

Short-term, rapidly accessed hardware for storing data – normally in the form of volatile semiconductor devices (loses data if it loses power).

Question 32

real-time system

Answer 32

A system which must guarantee to respond correctly to inputs within a specified time period.

Question 33

responsive / unresponsive

Answer 33

Acceptably fast / Unacceptably slow to respond to a request for action or information – the definition of acceptability depends on the context.

Question 34

scalable system

Answer 34

A system whose capacity can be increased, or less commonly decreased, to match changes in demand (where demand may be measured in number of users or amount of processing).

Question 35

scheduling

Answer 35

Allocation of processor (i.e. CPU) time between the various activities in a concurrent system.

Question 36

sequential system

Answer 36

A system in which each activity must complete execution before another activity can start.

Question 37

storage

Answer 37

Computer hardware for holding data in the long term (even after being powered down) – typically uses devices such as magnetic or optical disks that are slower but cheaper per unit of data than memory.

Question 38

TCP/IP

Answer 38

TCP (Transmission Control Protocol) and IP (Internet Protocol) are the most commonly used specifications of the detailed format of messages exchanged between internet hosts.

Question 39

terminal

Answer 39

A device for accessing a centralised computer system via local cablingor, if more remote, via the telephone system. Some terminals have limited processing ability, often to aid in graphical display, but the bulk of processing in the system is carried out on the central processor.

Question 40

time-sharing

Answer 40

A rather dated term for a concurrent system with a number of users that allocates time to each user, so that each has the impression that the computer is responding to just their request

Question 41

time-slicing

Answer 41

A scheduling approach for concurrent systems in which each activity gets a fixed and equal amount of processor time before the processing switches to the next activity.

Question 42

transparency

Answer 42

The extent to which a distributed system appears to its users as a coherent system providing a range of functions (so that the user does not need to know that the system is distributed).

Question 43

ubiquitous computing

Answer 43

Asituation where computing devices are so small and cheap that they occur in huge numbers throughout everyday environments.

Question 44

uniprocessor

Answer 44

A computer system with a single central processing unit (CPU).

Question 45

wide area network (WAN)

Answer 45

A computer network that spans a large geographical area such as a region, a country or the world and which typically relies on public providers of telecoms or other long-distance services for part of its communication path (in contrast to a LAN).