Cambridge International AS Level Information Technology

Vocabulary flashcards for key terms in the textbook.

Information

Data that has been given meaning.

Direct Data

Data collected for a specific purpose and used only for that purpose.

Indirect Data

Data obtained from a third party and used for a different purpose than originally intended.

Electoral Register

A list of adults who are entitled to vote in an election.

Data Brokers

Companies that collect and analyze some of an individual’s most sensitive personal information and sell it to each other and to advertisers and other organizations without the individual’s knowledge.

Accuracy of Information

Ensuring information is free from errors and mistakes.

Relevance of Information

Ensuring data captured is relevant to the purposes for which it is to be used.

Age of Information

Ensuring information is up-to-date.

Level of Detail of Information

Ensuring information has the right amount of detail.

Completeness of Information

Ensuring information deals with all the relevant parts of a problem.

Encryption

Converting information into a code which is impossible to understand without authorization.

Plaintext

Data before it is encrypted.

Ciphertext

Encrypted data.

Symmetric Encryption

The type of encryption where the sending and receiving computer have the same key to encrypt and decrypt a message.

Asymmetric Encryption

The type of encryption that uses two different keys- public and private.

Encryption Protocol

The set of rules setting out how the algorithms should be used to secure information.

IPsec (internet protocol security)

An encryption protocol suite which allows the authentication of computers and encryption of packets of data in order to provide secure encrypted communication between two computers over an internet protocol (IP) network.

SSH (secure shell)

An encryption protocol used to enable remote logging on to a computer network, securely.

Transport Layer Security (TLS)

The most popular protocol used when accessing web pages securely.

Validation

Ensuring data is reasonable and sensible.

Verification

Ensuring data has been copied or entered correctly.

Presence Check

A validation check to ensure data has been entered in certain fields.

Range Check

A validation check that the data is within a specified range of values.

Type Check

A validation check that ensures data is of a particular data type.

Length Check

A validation check performed on alphanumeric fields to ensure they have the correct number of characters.

Format Check

A validation check that can specify any specific combination of characters that must be followed.

Check Digit

A means of validating data using arithmetic. Used on numerical data stored as alphanumeric data-type.

Lookup Check

A validation check that compares the data that has been entered with a limited number of valid entries.

Consistency Check

A validation check that ensures data across two fields is consistent.

Limit Check

A validation check similar to a range check, but the check is only applied to one boundary.

Visual Checking

Verification carried out by the person entering the data, who visually compares the data they have entered with that on the source document.

Double Data Entry

Verification that involves the entry of data twice.

Parity Check

A verification method that makes sure that all bytes have an even number of 1s.

Checksum

A verification method used to check that data has been transmitted accurately from one device to another. Is used for whole files of data.

Hash Total

A verification method usually found by adding up all the numbers in a specific field or fields.

Control Total

A verification method calculated in exactly the same way as a hash total, but is only carried out on numeric fields.

Batch Processing

Processing large volumes of data that are collected over a period of time, entered, and processed together in one batch.

Master File

Contains all the important data that does not change often.

Transaction File

Contains the data that changes each week.

Sequential Access

When data is searched for in batch processing, each record is looked at one by one until the computer finds the record it is looking for.

Online Processing

The user is in direct communication with a central computer and data is searched using direct access.

Electronic Funds Transfer (EFT)

The electronic transfer of money from one bank account to another using computer based systems, without the direct intervention of bank staff.

Automatic Stock Control

The use of an automated system where stock is controlled by a computer with little human input.

EFTPOS

Electronic Funds Transfer at Point Of Sale.

Electronic Data Interchange (EDI)

A method of exchanging data and documents without using paper. The electronic exchange between computers uses a standard format.

Business-to-Business (B2B)

Refers to buying and selling between two businesses, rather than between a business and an individual customer.

E-Procurement

The process of obtaining goods and services through the internet.

Real-Time Processing

Requires the inputs to go directly to the CPU of the computer, but the response time of the computer must be immediate, with no delay whatsoever.

Real-Time Systems

They are systems where the output affects the input. Unlike other online systems, any output is produced quickly enough so that it affects the system before the next input is received.

Performance Metrics (Mainframe Computers)

Measures used to determine how well, or how fast, the CPU deals with data. Measured in millions of instructions per second.

Performance Metrics (Supercomputers)

Measures how many FLoating point Operations can be carried out Per Second (FLOPS).

Fault Tolerance

A computer with this means that it can continue to operate even if one or more of its components has failed.

System Software

The software that is used to run and control the computer hardware and its software resources.

Compiler

Software (a program) that processes statements written in a high-level programming language and converts them into machine code.

Interpreter

Translates the high-level language program one statement, or line, at a time into an intermediate form, which it then executes.

Linker

Combines object files or modules into one single executable file.

Device Driver

A small program that enables the operating system (OS) and application software to communicate with a hardware device.

Operating System (OS)

System software that manages computer hardware and software resources.

Utility Program

A type of system software that assists users in controlling or maintaining the operation of a computer, its devices or its software.

Formatting

Configuring of a data storage medium such as a hard disk or SSD for initial use.

Disk Defragmentation

Organizes the data on the disk by moving the data blocks around to bring all the parts of a file together so they are contiguous.

Data Compression

Modifying data so that it occupies less storage space on a disk.

Lossless Compression

The file is converted back into its original state, without the loss of a single bit (binary digit) of data.

Lossy Compression

Permanently deletes data bits that are unnecessary.

Back-up Software

A program used to keep copies of files from a computer or copy the content of a server’s backing storage.

Incremental Back-Up

One where only the data that has been added or changed since a specific date and time is backed up.

Differential Back-Up

Only backs up the data which has changed since the last full back-up.

Deleting

A utility program that is a piece of software which deletes the pointers that tell the OS where to find the file.

Anti-Virus Software

A program or set of programs whose function is to detect and remove viruses.

Custom-Written Software

Software which has to be specially written for a particular task and is developed for a specific company or business.

Off-the-Shelf Software

Software which already exists and is available straight away, ready for use.

User Interface

The means by which the computer system interacts with the user.

Command Line Interface (CLI)

A means of interacting with a computer using commands in the form of successive lines of text.

Graphical User Interface (GUI)

Uses windows, icons, menus and pointers (WIMP) to carry out commands.

Dialogue Interface

Allows a user to communicate with a computer or device using their voice.

Gesture-Based Interface

Is designed to interpret human gestures and convert these into commands.

Algorithm

A set of instructions sequenced to solve a problem or to represent a calculation.

Calibration

Making sure that when, for example, a temperature sensor is used to measure the temperature of boiling water, it actually causes the computer to output a value of 100 ºC.

One-Point Calibration

A method of calibration that consists of taking a reading from the sensor in the range being measured, comparing it with either a pre-calibrated sensor or a known value, subtracting the sensor reading from the known value, then adding the 'offset' to every sensor reading.

Two-Point Calibration

This method of calibration enables you to both apply an offset value and account for the slope of a graph.

Multipoint Calibration

A calibration strategy that means using some form of 'curve fitting'.

Gesture

Any physical movement, large or small, that can be interpreted by a computer. Examples of these are the pointing of a finger, nodding the head, or a wave of the hand.

Code Injection

It is any situation in which code is inserted or added into systems that did not intend for that code to be executed, and is now performed by an attacker.

Blacklist

A list a fake or untrustworthy sources.