A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z

H

HD - Hard Disk

A fixed (i.e. non-removable) mass storage medium with one or more disks and one or two read/write heads per disk. See also: FD.

HDCD - High Definition Compact Disc

A newer kind of CD-DA with higher sound quality. However, they can only be played on special CDPs and DVD players. See also: DVD, SACD.

HDF - Hierarchical Data Format

This file format for texts, tables, floating point data, bitmap images and color maps was developed at the NCSA. See also: BMP, GIF, IFF, JPEG, PBM, PCD, PGM, PNG, PNM, PPM, TIFF, XBM.

HFS - Hierarchical File System

This MacIntosh file system is used on some CD-ROMs for the Macintosh computer system.

Hi-Fi - High - Fidelity

HTML - HyperText Markup Language

This SGML application is the hypertext format of the documents in the WWW. The current standard is HTML 2.0 (written down in RFC 1866). The most important feature is the possibility to link documents using URIs.

HTTP - HyperText Transfer Protocol

This Internet protocol was designed for the WWW. There are different versions:

HTTP 0.9 (1989) - only for HTML files.
HTTP 1.0 (1990) - for all file formats.
Basic HTTP (July 1993) - first Internet draft - no RFC!
HTTP/1.0 (September 1995) - "Best Current Practice" - the minimum standard in the third Internet draft - no RFC!
HTTP/1.1 (Plan: April 1996): Shall become the HTTP 1.0 - RFC.
HTTP/NG (Plan: December 1996) - incompatible binary format - more efficient!

A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z