Cloud computing is a technique with Information Technology infrastructure as distributed computing and virtualization. Cloud computing provides low cost, scalable computation capacity and services to organization on demand for expansion. Cloud computing with many beneficial features also handling the difficulty of protecting the security of data outsourced by cloud users. This paper objective is provide different models of cloud computing and emphasize on data protecting and security ways.

KEYWORDS:  Cloud Computing, Service Models, Data Security, Data Masking Techniques.