Abstract: An overview of the basic concepts concerning context aware computing and a survey of the up-to-date researches were presented in this paper. Context and its spectrum were well formed and defined. Based on the evolution of computing modes, context aware computing as well as context aware systems was analyzed. As application examples, realizations of location based service and context aware web searching were discussed.

Key words: context aware, context model, context aware computing, context aware systems, context, context aware, context model, context aware computing, context aware systems