New semantic elements in HTML5

My dictionary defines semantics as “the branch of linguistics and logic concerned with meaning.” For our purposes, semantics is the process of giving our markup meaning. Why is this important?

Most websites follow fairly standard structural conventions; typical areas include a header, a footer, a sidebar, a navigation bar, and so on. As web authors, we will often name the divs we use to more clearly designate these areas (for example, <div class="Header">). However, as far as the code itself goes, any user agent parsing that content – and that includes a web browser, screen reader, search engine crawler, and so on – couldn’t say for sure what the purpose of each of these div elements is. HTML5 solves that problem with new semantic elements.

We won...