Also known as heading or header "tags" and "HTML Headings," H1s and H2s are HTML elements, and their primary purpose is to define a document's structure and to mark content as deserving of attention from search engines. For search engines, the text found between the opening and closing H1 tags is considered more important than the text found in H2 tags, which is more important than text for in H3 tags, etc.
The number of times any file on your web site is retrieved by a web server e.g. to view a web page an html file, an image file and a css file may be retrieved.
Hits are not the same as Page Views.
HTML is an acronym that stands for HyperText Markup Language. It is the core authoring language used to create world wide web documents. HTML is used to define the structure of web documents using tags and attributes, and is interpreted by a user's web browser.