1.What is Server?
+In the meaning of PHYSICAL server, a server is a REAL physical machine that we use to host for databases or websites
+In real world, a physical server is really powerful. Therefore, admin usually use software as VMWare to create logical machines inside it. It means that inside a physical machine, we can have many logical/virtual machines/servers.
2.Host V.S Server
+When we are taking about host, it is usually about the logical host
+When we are talking about server for a site, a database, it ALSO in the meaning of host
+The term server only can be understood as a physical server when we impress that we are talking about physical server
+The term server also can be understood as server software that installed into a host
3.Three Host Types
There are three types of hosts as:
+Dedicated Server: there is no logical hosts on this physical server. If you rent this server, it is just for you. This kind of server is suitable for large traffic sites
+Virtual Private Server (VPS): this is logical hosts in a physical server. You still have the right to control the host, but it is not as powerful as the dedicated server
+Shared Host: the most common used host. There are many shared hosts created in a dedicated physical server. Unlike the Virtual Private Server, shared host have a very limited access to the physical server resources