DITA Best Practices : Using Section elements

The section element represents a collection of organized information. It represents subsets of content that are related to a larger topic and are treated as siblings to each other. An optional title may be used. DITA has no H1H2, H3, etc. heading elements. Instead it has the section element which generally always has a <title> child element. Note: section elements cannot nest. 

Step-by-step guide