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IB SL Vocab(A-O)
Vocabulary from Appendix 1
Question | Answer |
---|---|
A-D converter | Analog-digital converter. A device for converting analog signals into digital ones for subsequent computer processing; sometimes called a "digitizer". A digital to analog (D to A) converter operates in the reverse direction. |
address bus | pathway from memory to processing unit that carries the address in memory to and from which data is transferred. See the definitions for "bus" and "data bus". |
algorithm | An ordered set of well-defined instructions for the solution of a problem in a finite number of steps. |
ALU | See the definition for "arithmetic and logic unit". |
analog data | The representation and measurement of the performance or behavior of a system by continuously variable physical entities such as currents, voltages and so on. See also the definition for "digital data". |
and | The output of "and" is True if all statements are True, False if any statement is False. |
applet(Java) | A program that runs in the context of a browser. |
application(Java) | A program that runs when translated by a Java compiler. |
archive | Data that represents a record of data held and processed at a specific time, which is held off-line for future research or for legal reasons. |
arithmetic and logic unit(ALU) | A part of the computer that performs arithmetic operations, logic operations and related operations. |
array | 1. An arrangement of data in one or more dimensions. 2. In programming languages, an aggregate that consists of data objects, with identical attributes, each of which may be uniquely referenced by indexing. |
ASCII: American Standard Code for Information Interchange | The primary encoding character set used in computers for textual data transfer between applications. The set uses eight bits for each character code, one of these bits being a check bit to verify the seven bits needed to represent one character. |
B | Byte. |
back-up(file) | A second copy of a file, to be used in the event of the original file being corrupted. |
bar code | A pattern of vertical lines distinguished for each other by width. It can be read by a bar code reader to provide data to a computer. |
bar code reader | An optical reader that can read bar codes. |
base | The basis of a notioin of number system, defining a number representaional system by postional representation. In a decimal system the base is 10, in a hexadecimal system the base is 16, and in a binary system the base is 2. |
batch processing | A method of processing data in which transactions are collected and prepared for input to the computer for processing as a single unit, for example, payroll. |
binary search | A search in which, at each step of the search, the set of data elements is divided by two, until the searched element is found. See also the definition for "sequential search". |
bit(b) | Binary digit. The smallest unit of information for data storage and transmission. Each bit is considered to be either a "0" or a "1". |
block | The smallest unit of data that can be transferred between memory and backing store in one operation. |
BMP | An extension given to files in bitmap form. |
Boolean expression | An expression that has a value of True(T) or False(F). |
bps | Bits per second. |
browser | Generally used to give interactive access to information on the World Wide Web, retrieving web pages and displaying in a multi-media format. |
bubble sort | A sort in which the first two items to be sorted are examined and exchanged if necessary to place them in the specified order; the second item is then compared with the third (exchanging them if required_, the third is compared with the fourth, |
buffer | A portion of storage used to hold input or output data temporarily. |
bus | The pathway used for sending signals between internal components of a computer. Components can share the same bus but cannot transmit simultaneously. See also definitions of " data bus" and "address bus". |
bus topology | A network in which all devices are connected to a common cable, known as the "bus". See also definitions of "star topology" and "tree topology". |
Byte(B) | A set of bits considered as a unit; it normally consists of 8 bits and corresponds to a single character of information. |
cable | Wire or glass fibre used to connect computers over a network. copper (coaxial and twisted pair) and glass fibre(fibre optic cable) are the most common. |
cache | Part of the main store that is between main memory and the processor. It holds a copy of data and instructions that are likely to be used next by the processor and is hence faster than main memory. See also the definition for "disk cache". |
CASE | computer-assisted software engineering - |
character set | A finite set of different characters that is complete for a given purpose, for example, the 128 ASCII characters. |
Check Digit | A digit added to numerical data that can be recalculated and hence used to check data integrity after input, transmission and so on. |
check sum | A sum generated using individual digits of a number and employed as an error-detecting device. |
class | Combination of data and operations that can be performed on the data; specification of the data members and methods of the object. |
client | Desktop computer or terminal used to access a computer-based system. |
client-server | A network architecture in which a system is divided between server tasks performed on the instructions received from clients, requesting information. |
collection | A class designed to hold objects(referred to in the syllabus as data structure). |
compiler | A program that translates a source program into machine code that can be converted into an executable program(an object program). See also the definition for "interpreter". |
computer-assisted software engineering | The automation of well-defined methodologies that are used in the development and maintenance of products. these methodologies apply to nearly every process or activity of a product development cycle, for example: project planing, product designing. |
computer architecture | The logical structure and functional characteristics of a computer, including the interrelationships among its hardware and software components. |
computer program | A sequence of instructions suitable for processing by a computer. |
constructor method | A method with the same name as the cass that initializes the instance variables of an object of the class when the object is instantiated. |
CRC cards | Class, responsibility, collaboration cards. A design tool for classes that lists a class's name, its responsibilities and the classes with which it collaborates on an index card. |
database management system(DBMS) | A computer-based system for defining, creating, manipulating, controlling, managing and using databases. |
data bus | The pathway between the memory or peripheral and processing unit that carries data for processing or data that has been processed. See also definitions for "bus" and "address bus". |
data compression | A method of reducing the size of data. All redundancy in the data is removed to reduce the storage needed or to speed up transfer. The data can be uncompressed back to its original state. |
data integrity | The correctness of data after processing, storage or transmission. |
data member | A data type that is a member of a class. |
data packet | Part of a transmitted message that is sent separately. Apart from containing a portion of the message it will have other data such as check digits, destination address and so on. |
data protection | Method of ensuring that personal data is correct and is not misused either by those holding it or others who have no right to access it. |
data security | Method of ensuring that data is correct, safe and cannot be read or changed by those who have no right to access it. |
DBMS | database management system. |
Debugging tool | A program used to detect, trace and eliminate errors in computer programs or other software. |
defragmentation software | An application that reads file segments from non-contiguous sections of a storage device and then writes the files to the same device in such a way that each file segment is contiguous. |
digital data | Discrete data |
digital signature | a digital code attached to an electronic message or document, which is unique and which can be used to authenticate the sender or owner. Most often used in electronic commerce. |
direct access file | A file organized in such a way that a calculation provides the address(location) of a record so that the record can be accessed directly. The records in the file may be ordered or unordered. |
disk cache | RAM set aside to speed up access to a hard drive. This may be part of the disk itself or may be incorporated in cache memory. |
distributed processing | A network in which some or all of the processing, storage and control functions, in addition to input/output functions, are dispersed among its nodes. |
encryption | In computer security, the process of transforming data into an unintelligible form in such a way that the original data cannot be easily obtained except by using a decryption process. |
exception | An object that is created when an abnormal situation arises in a program. See also the definition for "exception handler". |
exception handler | A program code that handles exceptions that arise during the running of a program. An exception is thrown to the handler rather than causing a fatal error. See also the definition for "exception".q |
expression | A sequence of symbols that can be evaluated. |
fibre optic | Cabling used for networking that uses fine strands of glass. The medium can carry a great deal of data and it gives a fast transfer rate. |
field(object attribute) | A subdivision of a record containing a unit of information. for example a payroll record might have the following fields: clock number, gross pay, deductions and net pay. |
file | An organized collection of data. |
file manager | An application software that can access, create, modify, store and retrieve files. |
flag | An indicator with two possible states, "set" or "not set", that can be represented by one bit, A flag can be used to indicate that a record can be deleted, to indicate end of input/output and to sense whether an interrupt has occurred. |
formal parameter | See the definition for parameter. |
formatted output | data prepared for output in order to be displayed in a desired format(for example, trailing zero on 7.50$ instead of 7.5$). |
graphics tables(graphics pad) | An input device in which the user writes or designs. The image is reproduced on the screen. |
GUI | Graphical user interface. |
hacking | Obtaining unauthorized access to protected resources. |
hexadecimal | A system of numbers with the base 16; hexadecimal digits range from 0 to 9 and from A to F, where A represents 10 and F represents 15. |
high-level language | A programming language whose concepts and structures are convenient for human reasoning. Such languages are independent of the structures of computers and operating systems. |
HTML(Hyper Text Markup Language) | A computer language used to construct web pages. Tags are used to denote the way in which text and graphics are to be displayed. The language is interpreted by a browser to display the pages. |
hub | In networking, a switch that sends data to the stations to which it is attached. |
IDE(integrated development environment) | A programming tool that gives programmers a single environment(that is, the hardware and software environment in which the program runs) for building programs rather than using individual editors and debuggers. |
identifier | The name or label chosen by the programmer to represent a variable, method, class, data type or any other element defined within a program. |
interface | The hardware and associated software needed for communication between processors and peripheral devices to compensate for the difference in their operating characteristics. |
interpreter | A program and translates and executes each instruction of a programming language before it translates and executes the next instruction. See also the definition for "compiler". |
ISO | International Organization for Standardization. |
iteration | The process of repeatedly running a set of computer instructions until some condition is satisfied. |
JPEG(joint photographic expert group) | A recognized standard for compression of graphics files that has some loss. |
latency | See the definition for "rotational delay". |
local area network(LAN) | A computer network where all the computers are directly linked by cables and/or microwave transmission. This is usually located on a user's premises within a limited geographical area. See also the definition for "wide area network(WAN)". |
local variable | A variable that is defined and is capable of being used only in one specified program block. |
logic error | An error arising from an incorrect appreciation of the problem leading to an incorrect action being performed and hence a false result being produced. |
magnetic ink character recognition | the identification of character through the use of magnetic ink. See also the definition of "OCR". |
mainframe | A computer, usually in a computer centre, with extensive capabilities and resources to which other computers may be connected so that they can share facilities. |
master file | A permanent file holding information that can be accessed and that is periodically updated by processing with a transaction file. See also the definition for "transaction file". |
memory address register(MAR) | Hold the address in memory of the instruction at present being executed. |
memory mapped I/O | See the definition for "DMA". |
menu | A display of a list of optional facilities that can be chosen by the user in order to carry out different functions in a system. |
method | 1. The behaviour or operation of an object. 2. The procedure used by an object as specified within the object class. see also the definition for "method signature". |
method signature | The number and types of arguments of a method. |
MICR | See the definition for "magnetic ink character recognition". |
microprocessor | An integrated circuit incorporating the main components of a central processor. These circuits are used for microcomputers and small devices controlled by computer. |
microwave transmission | a method of electronic communication that does not require cables. |
modem | am abbreviation for "modulator/demodulator": a piece of electronic equipment that converts digital signal from a computer into audio signals that are transmitted over telephone lines, and converts them back again. |
modular language | A language in which a complete program can be broken down into separate components(modules), each of which is to some extent self-contained. for example, the scope of variables can be limited to a module and does not extend through the entire program. |
modularity | One aspect of structured programming in which individual tasks are programmed as distinct sections or modules. One advantage is the ease with which individual sections can be modified without reference to other sections. |
module | A self-contained subset of a program. |
modulo arithmetic | Arithmetic tat uses the integer result and integer remainder of division as two separate entities. |
multi-tasking | A mode of operation that provides for concurrent performance, or interleaved execution, of two or more tasks. |
multi-user system | A system that allows two or more people to use the services of a processor within a given period of time. |
multi processing | The simultaneous execution of two or more computer programs or sequences of instructions by a computer(parallel processing). |
network | any set of interconnected computer systems that share resources and data. See also the definitions for "networking", "locall area network(WAN)". |
node | 1. In the terminology of tree structures, each position in the tree is called a "node". 2. any device on a computer network that can be addressed so that it can be contacted by other computers. 3. A "host" computer on a network. |
not | The output of "not" for a statement P is True if P is False, False if P is True. |
object | An object is a combination of data and the operations that can be performed in association with that data. Each data part of an object is referred to as a data member while the operations can be referred to as methods. |
object-oriented programming (OOP) | An approach to programming in which units of data are viewed as active"objects" rather than the passive units envisioned by the procedural paradigm. |
OCR Optical character recognition (reader) | Refers to the use of devices and software to "read" characters and translate them into ASCII characters for later processing. Applications of OCR include the scanning of printed documents to convert the text into ASCII text that can then be edited. |
OMR forms | Optical mark and read forms. |
on-line | When a user has access to a computer via a terminal. |
on-line processing (interactive) | Data processing in which all operations are performed by equipment directly under the control under a central processor, for example, airline reservations. |
operating system (OS) | Software that controls the execution of programs and that may provide services such as resource allocation, scheduling, input/output control, and data management. |
operator precedence | In programming languages, an order relation defining the sequence of the application of operators within an expression. |
or | the output of "or" is True if at least one input is true, otherwise the output is false. |
parity bit | A binary digit appended to a group of binary digits to make the sum of all the digits, including the appended binary digit, either odd or even as established beforehand. |
pass-by-reference | The parameter-passing mechanism by which the address of a variable is passed to the subprogram called. If the subprogram modifies the formal parameter, the corresponding actual parameter is also changed, In Java, all objects , including arrays, are this. |