Glossary

Header

In communications protocols, this is the control information that precedes the message or text portion of a block of data.

Hertz (Hz)

Unit of frequency, one cycle per second.

Horizontal Redundancy Checking (HRC)

Technique in which redundant information is included with a block of data for validating the transmitted data at the receiving end.

Host Computer

A computer that manages information for many terminals. A host computer may be mainframe, minicomputer or a microcomputer.

I

ID Name

See ID Number.

ID Number

A security code, used mainly with remote systems that either charge a subscription fee, allow the purchasing of goods and services on line or both. The code is known only to the user and protects the user from unauthorised access to her/his account. See also Password.

Input

Information transferred into a computer from some external source, such as the keyboard, a disk drive, a modem or a scanner. Also, the act or process of transferring such information.

Input/Output Device

A device that transfers information into or out of a computer.

Interface

A physical point of interconnection between two devices where electrical signal levels, timing, handshaking and pin numbers are defined. The devices, rules or convention by which one component of a system communcates with another.

Interference

Undesirable disturbances or distortions in a data transmission signal.

Intermediate Page

An index page which, when used with another index page, allows users to perform double-digit keying.

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Telenetics 56 Header, Hertz Hz, Horizontal Redundancy Checking HRC, Host Computer, ID Name, ID Number, Input, Interface