The hybrid cloud model is becoming quite famous as most of the Web host are offering this service and managing their hosting products. In this way they get to host their service virtually. Not only that, virtual server is cheaper as you get to host few sites under one virtual server. In each virtual server, you get to install its own OS and can install any software in the the specific domain. Each virtual server is isolated from the other virtual server. If any crash happens it will not effect the other virtual server.