Concept topics contain basic DITA elements, such as paragraphs, lists, images, tables, and many others. Most of these elements can be used in the other topic types (task and reference), as well. The only exception is the <conbody> element, which is specific to the concept topic type.
At a minimum, the concept topic must contain a <concept> root element (with an id attribute) that contains a <title> element.
After the <title> element and an optional <shortdesc> or <abstract> element, the <conbody> element contains the concept itself.
The <conbody> element has an open content model. This means that the elements contained in <conbody> are not required to follow a strict sequence. As long as an element is allowed inside <conbody>, it can appear in any order. The exceptions are the <section> and <example> elements, which can only be followed by other <section> or <example> elements or a <conbodydiv> element.
Video: Creating a DITA concept