Semantics

Semantics simply refers to something's meaning. What does this symbolize? Take the copyright symbol. We know what that means when we see it. We also know the @ symbol means at. These are examples of good semantics. These symbols have a clear purpose and meaning. We can use them with confidence that people will instantly understand what we mean, or what we want to say when we use them.

Writing semantics HTML simply means our elements should be used for the purposes they were intended. Lists should contain groups of similar items and content, headings should explain the content they're placed before, paragraphs should contain text (and should not be used to separate elements simply because they have a margin), and tables should contain tabular data and not be used for layout purposes.

These are semantics. However, where the semantics argument has divided people is whether class names and IDs describe the content also, or is it alright to have class names such as f-l p-10...