Here’s a great post on the Underused (But Semantically Awesome) Definition List, an HTML tag that I confess I almost never use myself. This article inspired me to take another look at it.
A quick intro to semantics
When we talk about semantics in HTML, we are talking about how HTML tags are used to describe the content. Good semantics means that the tags are being used well to describe the content. Bad semantics means that the tags being used poorly describe the content. Good semantics doesn’t necessarily mean that the least possible number of tags are used, only that the ones that are used make sense and, just as importantly, make sense used together. Bad semantics doesn’t necessarily mean that you used tags improperly either, that refers more to syntax.