Managing data in mobile computing environments always involve caching or replication. In many cases, a mobile device only has access to data stored locally, and a lot of data coming through the replication of other devices, PCs, and services. Such systems generally provide weak consistency model in which to read and update operations can be performed on each replica without coordination with other devices. The system may provide the best attempts, using a gossip protocol or multicast, or guarantee the consistency of the end for the communication pattern of arbitrary, using pairs developed recently, knowledge-driven protocol. Contents: Introduction Model Systems / / Data Consistency / Replicated Data Protocol / Replication Partial / Conflict Management Case Studies / / Conclusion / Bibliography