Hypertext refers to a word, phrase or chunk of text that can be linked to another document or text. Hypertext covers both textual hyperlinks and graphical ones. The term was coined by Ted Nelson in the 1960s and is one of the key concepts that makes the Internet work. Without hypertext, following a link on a topic to a related article on that topic – one of the primary means of navigating the Web – would be impossible.
Techopedia explains Hypertext
The concept of hypertext was central to the creation of the World Wide Web. Through the use of textual links, Web pages written in HyperText Markup Language (HTML) can be linked and cross-referenced throughout the Web. Ted Nelson actually had a far grander vision for hypertext than Tim Berners-Lee’s World Wide Web, but his project, Xanadu is still under development many decades later.
Nelson also coined the term hypermedia to refer to graphics, sounds and animations that could be similarly interlinked.