Cloud computing is an emerging phenomenon that offers on-demand, scalable, and elastic resources through a standard web service model. It allows for greater flexibility and cost savings compared to traditional computing models that are inflexible, expensive to procure and deploy, and difficult to upgrade. Large enterprises have requirements for world-class infrastructure, security, compliance, and premium service levels that cloud computing providers are addressing through managed hosting solutions that deliver dynamic capacity, real-time deployment, granular scalability, and zero capital expenditures.