Select the first letter of the word from the list above to jump to appropriate section of the glossary or type the term on which you want to search.

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H.264

an ITU standard for compressing a videoconferencing transmission based on MPEG-4. Formerly known as "H.26L," it uses Advanced Video Coding (AVC) to achieve up to a 70% reduction in bandwidth over H.263. The encoding scheme is also known as "MPEG-4/AVC" and "MPEG-4 Part 10."

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hack

to alter a computer program or gain unauthorized entry into a program, computer, or computer system.

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hacker

though the term has been associated primarily with people who endeavor to violate computer or software security in some manner, the primary definition refers to an individual who is exceptionally skilled as a computer programmer. The other common meaning for the word is someone who gains unauthorized entry into a computer system or software program for the sake of mischief or financial gain. In light of many of the malicious deeds and pranks being played of late, such as the malicious introduction of viruses via email, and the intentional crippling of large Websites such as Yahoo, the accepted use of the term is unfortunately becoming negative. see cracker.

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half duplex

the transmission of data in only one direction at a time. see full duplex.

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hand icon

the image the mouse cursor takes on when it is pointed to a hyperlink.

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hand-held computer

a battery operated computer small enough to hold in a user’s hand. Hand-held computers offer features such as an address book, organizer, calculator, Internet access, and games. One limitation of the device is a keyboard that is difficult to use, though this has proved to be a minor drawback as the electronic pen has become the method of choice for keyboard or screen keying functions.

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handle

a name used in a chat room, bulletin board or other online discussion forum. For example, Marjie’s online handle is Fidgetywitch.

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handles

in a graphic design program, an object appears superimposed over an outlined box. Each of the corners and midpoints of the box are the grips or handles used by the artist to manipulate the image. see bounding box.

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handshake

the communication between two modems that indicates a connection is being made.

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hang

a kind of computer crash that makes communication between the keyboard and computer impossible with the exception of utilizing the Ctrl-Alt-Del function. Doing so will offer the user the option to close the active application or reboot the computer. see Ctrl-Alt-Del, crash.