Cloud service providers charge users depending on the space or service provided.

In R & D, it is not always possible to have the actual cloud infrastructure to conduct experiments. For any academic, academic or scientific researcher, it is not feasible to hire cloud services at a time and then run their algorithms or implementations. For research, development and testing purposes, open source libraries are available, which gives the feel of services on the cloud . Nowadays, in the research market, cloud simulators are widely used by researchers and professionals, without the need to pay any amount to a cloud service provider.