What is DITA-xml
Darwin Information Typing Architecture (DITA) is a standard XML-based architecture for representing documents intended primarily for consumption by humans. It provides architectural features for content modularity, content reuse, and controlled extension of document vocabularies in a way that ensures interoperability of DITA documents.
The DITA architecture was originally developed inside IBM for IBM technical publications, especially Web-based content, and donated to OASIS Open in 2004.
Figure 1. Slide showing the evolution of DITA-xml
Recommendable videos describing DITA we can refer to the following: