What is semantic markup?
In English, the word semantic means “of or relating to meaning”… In markup, semantics is concerned with the meaning of an element, and how that element describes the content it contains. Semantically markup is about using html elements to give content meaning. This is important for a wide range of user agents (browsers without style sheets, text browsers, PDAs, search engines etc.) You should use standard HTML elements for your markup and avoid styling HTML elements to look like other HTML elements.