This document discusses cloud computing and its impacts on business and IT. It begins by explaining the evolution of technologies from mainframes to cloud computing. Cloud computing transforms IT and enables big data analytics. Worldwide device shipments are increasing, especially for smartphones and tablets. This ushers in a post-PC era where mobile internet access is most common. The internet of things and wearable devices are emerging trends. Cloud computing is already widely adopted and provides on-demand services over the network. In Thailand, the cloud market is growing significantly each year but maturity levels still vary between infrastructure, platform and software services. Both opportunities and challenges exist in security, skills and regulations. Organizations should develop cloud strategies and integrate cloud into their IT architecture