There are four parts to today's hypermedia:
1. Linking: the ability to define, manage, display, traverse links between spots in the information,
2. integration of data types: mixing of text, video, graphics, sound, spreadsheets etc.
3. Scripting: the presence of an interpreted programming language to help define semantics of a link traversal,
4. information retrieval: the ability to find information by a dynamic search (ie. not by following a predefined link) on 
text strings.


All real hypertexts incorporate IR techniques.