My question is: where did you come across this and what body are your referring to? If they didn't appear in the body, that is.
Tags follow the same pattern <tag>something</tag>. First part opens the tag, second part </> closes the tag.
<h#></h#> are headlines that are like titles to articles, 1 is biggest and decrease in size as per number 2,3,4, each getting smaller. They can be used as main headlines (i.e. h1) and sub-headlines (h2, h3, etc.)
Hope this helps. Regards.