Semantics is the study of the meanings of words and phrases in language, so a semantic element clearly describes its meaning to both the browser and the developer. Some non-semantic elements are <div> and <span> which tells nothing about its content. On the other hand the semantic elements like <form>, <table>, and <img> clearly defines its content. HTML5 semantic elements are supported in all modern browsers but you can "teach" older browsers how to handle "unknown elements" by:
