1. Cloud provides computing services such as storages and software over internet
2. Physical infrastructure is hardware components used for computing, we need separate space for physical infrastructure, such as physcial servers and storage ddevices

3.Virtual infra provides physical infrastructure benefits through a software, it does not require separate space for it.

4. the key difference is physical need separate space and it is costly, used by private industry

virtual infra is cost effective, does not require separate space for it, used by shared industries