Grid Computing has become an important field of research, which has evolved from conventional Distributed Computing and High Performance Computing for solving large-scale problems. Scientific and business applications are very complex and it requires massive computing power and storage space. Grid Computing environment supports the technology to execute large-scale applications on Resources. Resource Allocation and Task Scheduling have received much attention from the research community in the Grid computing because of some desirable properties like optimum utilization of resources, improvements in minimize of waiting time, total completion time and total response time and Total Resource Cost. The scheduling of tasks for the heterogeneous computing resources has been examined by many scientists and has been established to be an Non deterministic Polynomial complete problem.