Sure.
Usually an author tries to have just a few level 1 headings, and divides the text between level 1 headings with level 2 headings. Long documents might use more levels of headings. For example, a book-length document would use level 1 headings for chapter titles, level 2 headings for the main sections within a chapter, and perhaps level 3 headings for fine divisions of a section.
Here is a Web page with some headings in it. Click on the button to see how your browser displays them. Change the level of some of the headings to see what happens.
Play with the Web page:
</h1> tag and observe the effect.<h1> tags to a level that does not exist (such as 7).
