Josh References Glossary H

H&H
See Hoot & Holler (H&H).

hacker
One who uses a computer beyond its original design to accomplish a task. See also cracker.

header
The first five bytes of an ATM cell, containing information on flow control, virtual path and channel, payload type, cell urgency, and a header-only checksum.

HFS
See Hierarchical File System (HFS).

Hierarchical File System (HFS)
(General) A structured, hierarchical file system, such as the fast file system (FFS) or the Unix File System (UFS).
(Specific) The hierarchical file system used on the Macintosh system in MacOS 6 through MacOS 9. Deprecated in MacOS X.

High Performance Peripheral Interface (HiPPI)
A high-speed (800Mb/sec or 1.6Gb/sec, depending on the width) network interface connection, typically to one or more mainframes or supercomputers.

HINFO record
See DNS record types, HINFO record.

HiPPI
See High Performance Peripheral Interface (HiPPI).

High Speed Serial Interface (HSSI)
A serial interface that runs on high speeds.

Hoot & Holler (H&H)
A dedicated point-to-point voice facility between international offices of a trading facility.

hop
A direct path from one node to another, with a hop count of 1. See hop count.

hop count
A measure of distance between two nodes in an internet. A hop count of n means there are n-1 gateways between the source and the destination nodes.

host
A computer, router, or workstation which may or may not be on a network.

host alias
A nickname for a host, such as "chimailhost" for the machine in Chicago that handles mail.

host part
The host-specific portion of a CIDR address. The host part identifies the specific interface on a host.

hot spare
A disk partition reserved for use in a stripe or mirror metadevice; in case an existing partition fails use a hot spare to recover data in place with no downtime and no data loss. See also Disk Suite.

HSSI
See High Speed Serial Interface (HSSI).

HTML
See HyperText Markup Language (HTML).

HTTP
See HyperText Transport Protocol (HTTP).

hub
Network hardware than centralizes a number of network terminal or workstation connections in a single area.

human engineering
See ergonomics.

hypertext
A method of presenting information where selected words in online text can be "expanded" into more information.

HyperText Markup Language (HTML)
A subset of the US government's Standardized General Markup Language (SGML), HTML is the underlying base of the World Wide Web (WWW). Even though SGML has a static definition, HTML is expandable because SGML defines a process for extending its subsets of tags. Defined in RFC 1866.

HyperText Transport Protocol (HTTP)
The protocol in the Internet Protocol (IP) family used to transport hypertext documents across an internet. Defined in RFC 1945 (v1.0) and RFC 2616 (v1.1)