From the last few years, the value of cloud computing is increasing because it is major technology solution for business & organizations around the world. Cloud computing is a recent concept that gives new technology model for IT services which save time & money also. This paper discusses definition of cloud computing. What is cloud computing? What are the types of cloud computing? What are the cloud computing services? How these services can be the solutions for libraries? What are the various examples of each cloud computing types & services? Cloud computing solutions can create the new workflows needed by libraries because it offers the opportunity for a co-operative platform for libraries to build on. There are four principles of a cooperative platform, viz. Openness, Extensibility, Data richness & collaboration. Libraries have the opportunity to improve their services & relevance in today's information society. Cloud computing is one avenue for this move into the future. It can bring several benefits for libraries & give them a different future. This paper discusses mainly the types & services offered through cloud computing. SaaS, PaaS & IaaS are three main services. Also this paper focuses on application of cloud computing in Academic library.