The section element represents a generic section of a document or application. A section, in this context, is a thematic grouping of content, typically with a heading.
It further explains that a section shouldn’t be used as a generic container that exists for styling or scripting purposes only. If you’re unable to use section as a generic container—for example, in order to achieve your desired CSS layout—then what should you use? Our old friend, the div—which is semantically meaningless.
Some examples of acceptable uses for section elements include: