There has been a vast advancement in mobile wireless communication since the last few decades. This innovation consists of a number of generations and is still going on. The journey of mobile wireless communication began with 1G followed by 2G,3G,4G and under research upcoming generations 5G. In this paper, an attempt has been made to provide an overview of evolution of mobile generations by comparing the standards, data rates, capacity, primary service, challenges and features provided by each generation and explaining how improvements have been made from earlier generation to the next one.