Terms - H

H.320 - videoconference standard

A standard describing classical videoconferences for ISDN. The transmission rate depends upon the number of B-channels through which the connection is made.

H.323 - standard for data transmission on IP networks

A standard defining a transmission of video and voice through packet switching networks.

H.324 - videoconference standard

A standard defining a videoconference connection within PSTN through analogue modems.

HDSL - High bit rate Digital Subscriber Line

A technology using two or three copper pairs for transmission at rates of 1.5 Mbit/s and 2.2 Mbit/s, respectively.

HFC - Hybrid Fiber/Coax

An access network comprised of optic and coaxial cables.

HTML - HyperText Markup Language

A coding language used for development of formatted documents on the World Wide Web (WWW). HTML is a text code and is used to format a so-called tag (a sort of label). Its speciality (and the reason why HTML was chosen as the WWW format) is the reference: The code in the HTML language refers to another file (a picture, another HTML file, Internet service, etc.). A client program (such as a browser) provides fast access (just by a mouse click) to those elements to which the references are made.

HUB

A splitter (concentrator, repeater) connecting nodes in the star network topology.

Hardware

An aggregate of tangible technical means providing for or extending operations of the computer system. Hardware is the computer itself, its components (memory, motherboard with its circuits, recording media, peripheral units, I/O equipment, additional cards, etc.), printers, networks and special equipment. Hardware is all but the software. Firmware is something between hardware and software.

Help Desk

A nonstop service where the user may obtain information around the clock (i.e. 24 hours a day, 7 days a week).

Host

A computer on a data network. This designation is especially used for servers.

Hypertext Transfer Protocol (HTTP)

A protocol used for transporting hypertext files on the Internet. For its function it requires not only a server that is capable of handling such function (an http server) but also a client program that co-operates with this server (client HTTP). It is the most important WWW protocol.