The Reuse feature in the Topic Editor enables you to reuse content using direct and indirect references. You can do this by inserting content references, key references, or content key references to identify elements in a topic or map for reuse. You can also reuse entire topics or maps using topic references and map references.
When you reuse content, you create the content once, then reference that content in other resources, like topics and maps. This eliminates the need to copy and paste content that you want to reuse. Since there is only one source of the content, you can make updates in the source file and the updates display in all files that reference that content.
There are three common methods of reuse in easyDITA:
Topic and Map Reuse (topic references, map references, and key references)
Element Reuse (content references)
Variables (content key references)