Cloud computing provides on demand large scale hardware and software services over the internet. It is a group of virtual servers available for general public through payment. On the other hand, grid computing is a collection of heterogeneous distributed resources to solve large scale problems with intensive resources. Grid computing allows an application to run on different machine and utilize the grid resources. This paper describes the layered architectures of two computing models, mapping of layers in terms of services and their functionality differences. The audience of this paper is academia.