What is a DITA concept?

DITA concept topics answer "What is..." questions. 

Concepts provide background that helps readers understand essential information about a product, interface, or task. Often, a concept is an extended definition of a major abstraction such as a process or function. Conceptual information may explain a product and how it fits into its category of products. Conceptual information helps users to map their existing knowledge to tasks and other essential information about a product or system.

Concept structure

The < concept > element is the top-level element for a DITA concept topic. Every concept contains a < title > and a < conbody > and optional < titlealts >, < shortdesc > or < abstract >, < prolog >, < related-links >, and nested topics.