Context-aware platforms target to bring a wealthy consumer adventure via taking into account the present person context (location, time, job, etc.), possibly captured with out his intervention. for instance, mobile phones are actually capable to continuously replace a user’s situation whereas, even as, clients execute an expanding volume of actions on-line, the place their activities might be easily captured (e.g. login in an internet program) with no consumer consent. within the final decade, this subject has visible various advancements that show its relevance and value. The trend used to be speeded up with the widespread availability of robust cellular units (e.g. smartphones) that come with a myriad of sensors which allow functions to trap the person context. in spite of the fact that, there are a number of demanding situations that has to be addressed; we specialize in scalability (large variety of context acutely aware messages) and privateness (personal info that could be propagated). This e-book is equipped in 5 chapters beginning with an creation to the subject matter elevating an important demanding situations. Then, bankruptcy offers numerous important definitions (establishing a standard flooring for the next chapters) and taxonomy. These are very important to bankruptcy 3 which describes the most correct distributed context-aware structures that may be labeled in keeping with the taxonomy. privateness is addressed in bankruptcy 4 and chapter five presents a few vital conclusions. The viewers for this publication is large; researchers, scholars and execs in the components addressed will locate the main proper information about scalability and privateness in distributed context-aware systems.