Cloud computing is not a technology revolution, but rather a process and business evolution in terms of how we use those technologies that enable cloud computing as it exists today (Xiong & Perros, 2009). Cloud computing is based on the idea of renting out servers, storage, networks, software technologies, tools and applications as utilities or services over the internet as and when required in contrast to owning them permanently (Alford, 2009). Before analysing the impact of cloud computing for GSD it will be useful to define the general service types and deployment models for cloud computing.