Hacker 
Halftone 
Hand-held scanner 
Handle 
Handshaking 
Hang 
Hard copy 
Hard disk 
Hardware 
Hardware compatibility 
Hardware dependent 
Hayes-compatible 
Head 
Header 
Help 
Help key 
Hewlett-Packard LaserJet 
Hexadecimal, hex or H 
Hidden files 
Hierarchical filing system 
High memory area (HMA) 
Highlight 
History 
Home key 
Horizontal scroll bar 
Hot key 
Hotspot 
HTML 
HyperTerminal 
Hypertext 
Hyphenation and justification