In technical communication, topic-based authoring is a modular approach to content creation where content is structured around topics that can be mixed and reused in different contexts. It is defined in contrast with book-oriented or narrative content, written in the linear structure of written books.
This authoring approach is popular in the technical publications and documentation arenas, as it is adequate for technical documentation. Tools supporting this approach typically store content in XML document format in a way that facilitates content reuse, content management, and makes the dynamic assembly of personalized information possible.
A topic is a discrete piece of content that is about a specific subject, has an identifiable purpose, and can stand alone (does not need to be presented in context for the end-user to make sense of the content). Topics are also reusable. They can, when constructed properly (without reliance on other content for its meaning), be reused in any context anywhere needed.
The Darwin Information Typing Architecture (DITA) is a standard designed to help authors create topic-based content. The standard is managed by the Organization for the Advancement of Structured Information Standards (OASIS) DITA Technical Committee.