Grid computing is a farm networking which focus on the power of many computers in network to solve problems requiring a large numbers of processing cycles and involving huge amount of data in grid computing PCs and servers . The goal of grid computing is to create the illusion of a simple yet large and powerful self managing virtual computing out of large collection of connected heterogeneous system sharing various combinations of resources. It is nothing but a processor architecture that combines computer resources from various domains to reach a main objective. In grid computing, the computers on the network can work on a task together, thus functioning as a supercomputer. This paper discusses the overview of grid computing and its related key terms; evolution of grid computing, its types, requirements, architecture, current developments and its real world application.