COMMENTS
Comments are lines of code that do not show up within a web browser. Rather, they remain hidden within the source code of a page as a form of note taking or reference for the person writing the code.Comments begin with <!-- and end with -->. All text inbetween will not show up in a browser. That text can even span multiple lines of code. For example:
<!-- This text right here will not be displayed..
and neither will this text -->
Comments are useful for removing blocks of code when testing different elements on a site. They can also be extremely useful when working on a page with multiple authors.