A context is a model used by a service to perceive and interpret the world. >

The environment is used by the context to access configuration properties. >

A service represents an entity that emits and receives signals and has a status. >

A signal is a classification of a service operation or interaction outcome. >

A status is an inferred quality of service derived from signals emitted or received. >

The orientation is used to indicate the method of signaling or status change. >

A subscriber is used for registering interest in signal or status changes. >

The subscription is used for unregistering interest in signal and status changes. >

A variable is used for efficiently retrieving a value from an environment. >