html describes the structure of the web pages using markup what does that mean??

Answer 1

Markup is a piece of information attached to a document that describes how the document should be formatted by the typist. HTML is an electronic markup attached to the web documents that tell how they should be formatted by the browser. It describes the structure of the page. It tells that this is a paragraph and this is an header. This should be bold and this should be italics. Hope this helps

Answer 2

In computer text processing, a markup language is a system for annotating a document in a way that is syntactically distinguishable from the text.[1] The idea and terminology evolved from the "marking up" of paper manuscripts, i.e., the revision instructions by editors, traditionally written with a blue pencil on authors' manuscripts.
(Information from Wikipedia)

Answer 3

It means that each piece of page must be tagged accordingly. For example you should put main part to main tag, paragraphs to p tag. The correct markup also benefits in accessibility and seo. I hope it helps