Delay Tolerance Network (DTN) is a network used in large time delays communications long distance such as space communications and used in an environment where there is no end to end path connectivity. The messages are delivered using store and forward mechanism. There exists a variety of different types of mobility models in DTN like Random Mobility Models (RMMs), Map Based Mobility models (MBM) etc. which play important role in evaluating DTN protocols. Various types of mobility models have been reviewed in this paper. The pros and cons of various mobility models have been studied along with their characteristics.