11. A context providing apparatus comprising: a context holding unit comprising a memory device, the context holding unit configured to record a plurality of context information, wherein each context information includes a context entity identifier for distinguishing a context entity from other context entities, various information representing a state of the context entity, and association information; a context request reception unit configured to receive a request for information representing the state of a first context entity; a context generation unit configured to, in response to the request received by said context request reception unit, from said context holding unit, extract the context information of the first context entity, extract the context information of a second context entity which is registered as the association information in the context information of the first context entity, and execute, at least once, a process of extracting the context information of a third context entity which is registered as the association information in the extracted context information excluding the context information of the first context entity, but not registered as the association information in the context information of the first context entity, to determine, as the information representing the state of the first context entity, the information contained in any of the extracted context information; and a context transmission unit configured to send back the information determined by said context generation unit to respond to the request.
11. A context providing apparatus comprising: a context holding unit comprising a memory device, the context holding unit configured to record a plurality of context information, wherein each context information includes a context entity identifier for distinguishing a context entity from other context entities, various information representing a state of the context entity, and association information; a context request reception unit configured to receive a request for information representing the state of a first context entity; a context generation unit configured to, in response to the request received by said context request reception unit, from said context holding unit, extract the context information of the first context entity, extract the context information of a second context entity which is registered as the association information in the context information of the first context entity, and execute, at least once, a process of extracting the context information of a third context entity which is registered as the association information in the extracted context information excluding the context information of the first context entity, but not registered as the association information in the context information of the first context entity, to determine, as the information representing the state of the first context entity, the information contained in any of the extracted context information; and a context transmission unit configured to send back the information determined by said context generation unit to respond to the request. 15. The context providing apparatus according to claim 11 , further comprising a rule holding unit that holds a predetermined rule, wherein said context generation unit is further configured to determine the information representing the state of the first context entity in accordance with the rule held in said rule holding unit.