Nowadays a fast growing computing technology is the public cloud computing technology. Cloud computing is the delivery of computing services—servers, storage, databases, networking, software, analytics and more—over the Internet (“That is the cloud”). Companies offering these computing services are called cloud providers and typically charge for cloud computing services based on usage, similar to how you are billed for water or electricity at home. Cloud is fast becoming the new normal. By the end of 2015 it’s estimated that 90% of UK businesses will be using at least one cloud service. This article focuses on effect of public cloud computing in public limited in past few years.