Concepts are much like Categories, except that they are computed dynamically from semantic information. As such, they are more flexible and can replace categories in many cases. In addition, they can be nested, i.e. a concept can be used in a semantic query. This often simplifies queries a lot.

Using the most base category only, e.g. "Region" and putting all the details into semantics, allows us to form concepts. For most contributors, that means simply using [[Concept:(something)]] instead of [[Category:(something)]].

New concepts are easily defined as well:

{{#concept:  [[Category:Regions]] [[located on::Atamara]]
| Regions of Atamara
}}

Not only can "Regions of Atamara" be implemented as a concept, but so could "Cities", and "Regions on the coast", etc.

Once a concept is created, you can use [[Concept:Regions of Atamara]] in your queries like you would a category or property, and it will all automagically be updated with changes, etc. For example: We have defined a concept "Duchies" below (a region that is of type city or stronghold). Now we do not have to update a potentially large number of pages when the concept of a duchy changes (e.g. when for some reason we make it possible for townslands to be a duchy center, or if a new region type is introduced, etc.)