The two main units of authoring in DITA are topics and maps. Each
can be extended into new structural types and domains through
specialization.
DITA topics
DITA topics are the basic units of DITA content. Each topic should be organized around a single subject.
DITA maps
Maps organize topics for output to a specific deliverable, including generating navigation files and links to related topics.
Common metadata elements
The same metadata elements are available in both DITA topic types and DITA map types. This allows the metadata assigned to a topic when it is created to be supplemented or overridden when the topic is included in a collection.
Common attributes
The following attributes are common across most DITA elements.