  Computation encounter the new approach of cloud computing which maybe keeps
the world and possibly can prepare all the human's necessities. In other words,
cloud computing is the subsequent regular step in the evolution of on-demand
information technology services and products. The Cloud is a metaphor for the
Internet and is a concept for the covered complicated infrastructure; it also
depends on sketching in computer network diagrams. In this paper we will focus
on concept of cloud computing, cloud deployment models, cloud security
challenges encryption and data protection, privacy and security and data
management and movement from grid to cloud.
