Cloud hosting is a web hosting environment in which several servers are connected to one another to form a cloud which acts like a single server when providing web hosting services to the hosted websites. The setup also involves a lot of virtualization too, and even if a few servers in the cloud go offline, the remaining servers keep working as a cloud and continue to provide hosting services to the hosted websites. Cloud hosting is much more reliable than any other type of web hosting service and offers several features like auto-scalability, flexibility, stability, security etc
VPS hosting is a web hosting environment in which several virtual servers are created on a single physical server, each of which acts like a unique server and acts independently. VPS servers are like mini-dedicated servers, each VPS has its own quota of RAM, CPU, bandwidth, storage etc. But VPS hosting is not as reliable as cloud hosting because if the main physical server goes offline for any reason, all the VPS servers created on that server go down too, this is where cloud hosting has advantage over VPS hosting.
Dedicated server hosting is a web hosting type in which a full dedicated server with all its resources like Storage, RAM, CPU, bandwidth etc are for you to use and you are not going to share your dedicated server with anyone else, unless you are willing to, with your friends or family etc. Dedicated servers are expensive (depending on the specs you choose), but still dedicated servers are not as reliable as cloud hosting services because those are still a single server each and if that goes down for any reason, all the websites hosted on that server go down too.
