Resource Query Language
The Resource Query Language (RQL) is used to identify resources that meet a defined set of criteria. An RQL query returns a set of resources that match the criteria expressed in the query. Work can then either be allocated to one of those resources, or offered to multiple individual resources.
RQL is dynamic, and is evaluated when the work item is created and whenever it changes. This means that if the items referred to by the RQL change in some way (for example if the resources mapped to an organizational position are changed) this will be reflected in the set of resources associated with the work item.
See Assigning Participants to a User Task for details of how RQL is used.
You may want to consider whether to use Resource Query Language or Dynamic Organization Participants. See Dynamic Organization Participants.