Semantic HTML is one of those things that comes up in every accessibility talk. If you’re a developer, you’re probably tired of hearing about it. The thing is though that it’s vitally important, and is the foundation of every accessible thing on the web. It’s also the foundation you need to start with if you’re trying to make that cool thing you’re building accessible to everyone, no matter what kind of device they use to access your site or web application.
Léonie Watson has posted a very well-written article explaining what “semantic” means in the context of the web, along with some demonstrations. It’s worth a read for anyone who’s making things on the web, (including people who don’t consider themselves developers), and it can serve as a quick reference to file away for later when you’re in the middle of building and you need a reference.