What is mark up language?

Answer 1

In computing, "mark up" is "a set of tags assigned to elements of a text to indicate their relation to the rest of the text or dictate how they should be displayed".
Ref: http://lmgtfy.com/?q=mark+up+meaning
Mark up languages are hence languages which enable you to assign these tags to text.

Answer 2

This question has already been asked before.
https://www.sololearn.com/discuss/1687937/?ref=app

Answer 3

thank you very much