Abstract: Cloud computing is one of the most popular recent emerging technology of Information technology. Cloud Computing enables us to use the hardware and software resources over the internet according to the requirement of the user on pay per use basis. Cloud Computing devices being able to exchange large amount of data such as images, audio, video, text files as well as business information with the help of internet. As all the data is being stored in clouds, security issues should be addressed properly. All the organizations have concerns about security, privacy, residency, unauthorized access, fabrication, interception, interruption, modification and non-repudiation so security should be properly implemented in cloud computing architecture to properly implement it in businesses. In this paper we will discuss about the cloud computing, working of cloud, different cloud computing deployment models and service models.

Keywords: Cloud Computing, IaaS, PaaS, SaaS, Virtualization.