Location

Can be of four basic types: semantic (or symbolic), relative, absolute, physical. In the context of some methods, state is equivalent to location.

Semantic
Semantic locations are symbolic locations described in a natural language way. Semantic locations are a popular concept in context-aware or location-aware mobile computing. Semantic locations are things like room names or building names. Sometimes referred to as room-to-room or room-level.

Symbolic
For our purposes, a symbolic location is the same as a semantic location. It has no coordinates, but is represented by a name like "My room" or "John's office". Occasionally used as an alias are the words zone or area.

Relative
A relative location is a location that uses its own frame of reference based on proximity to reference points.

Absolute
An absolute location is a location that uses a shared reference grid with all other locations.

Physical
A physical location uses coordinates, like degrees, minutes, and seconds (GPS).