Cloud Computing Grid Computing
Grid Computing refers to distributed computing, in which a group of computers from multiple locations are connected with each other to achieve a common objective. These computer resources are heterogeneous and geographically dispersed.
Grid Computing breaks complex task into smaller pieces, which are distributed to CPUs that reside within the grid.
Utility computing is based on Pay-per-Use model. It offers computational resources on demand as a metered service. Cloud computing, grid computing, and managed IT services are based on the concept of utility computing.