How many header tags in html?

Question

Header tags is used to size of text of normal or large in web browser.

Answer 1

if I understood you correctly, in html there are 6 tags for text formatting. h1 is the largest text. h6 is the smallest one.

Answer 2

<h1> to <h6> are default styled from largest text to smallest, but you could style them as you want...
However, less than use them according to their size, you must try to use them as semantically hierarchycal headers: <h2> is kind of subtitle of <h1>, and so on...
Also, it's usually advised to limit the use of <h1> only once per page, as main title of the page content ;)

Answer 3

What are the main uses of scanf & printf in c & c++?