hypertext mark-up language vs HTML

hypertext mark-up language and HTML both are nouns.

Word	Noun	Adjective	Verb	Adverb
hypertext mark-up language	Yes	No	No	No
HTML	Yes	No	No	No

As nouns, hypertext mark-up language and HTML are synonyms defined as:

hypertext mark-up language and HTML: a set of tags and rules (conforming to SGML) for using them in developing hypertext documents

Other synonyms of hypertext mark-up language include hypertext markup language.

hypertext mark-up language (noun)	HTML (noun)
a set of tags and rules (conforming to SGML) for using them in developing hypertext documents	a set of tags and rules (conforming to SGML) for using them in developing hypertext documents