5.2 Exploring the Profiles of OWL

	Both the original OWL specification and OWL 2 provide profiles or sublanguages of the language that give up some expressiveness in exchange for computational efficiency.
	Profiles introduce a combination of modified or restricted syntax and nonstructural restrictions on the use of OWL.
	There were three species of OWL: OWL Full, OWL DL, and OWL Lite. OWL Full was the full, unrestricted OWL specification. OWL DL introduced a number of restrictions on the use of OWLFull, including the separation of classes and individuals. OWL Lite was essentially OWL DL with a subset of its language elements.
	The main purpose of an OWL profile is to produce subsets of OWL that trade some expressivity for better computational characteristics for tools and reasoners.
	The profiles were developed with specific user communities and implementation technologies in mind.
	There are three standardized profiles of OWL: OWL EL, OWL QL, and OWL RL. Each profile is defined by restricting OWL DL.

		OWL EL: The OWL EL profile is designed to provide polynomial-time computation for determining the consistency of ontology and mapping individuals to classes. OWL EL is a syntactic restriction on OWL DL.
		OWL QL: The OWL QL profile is designed to enable the satisfiability of conjunctive queries in log space with respect to the number of assertions in the knowledgebase that is being queried. This profile was based on work involving the virtual integration of databases.
		OWL RL: The OWL RL profile is designed to be as expressive as possible while allowing implementation using rules and a rule-processing system.