Yes, you can upgrade your server's specification at any time. You may also "add-on" additional hardware, software, and features to your server as required. 

Within the Web hosting industry, a Data Center is a facility used to store and manage Web sites and other Internet information and hardware infrastructure. These Data Centers contain computer servers connected to the Internet 24 hours a day, 7 days a week. Redundancy is a common theme found within high quality data centers and also can be implement

Dedicated server on steam is a server that gives you control and root access to your server machine. This is basically for users who want to setup a game server using steam cmd. It is a command-line version used to deploy and update the different dedicated servers that run PC games available on Steam.

Virtual private servers are different from dedicated servers in that instead of running one hosting account on one computer/server, virtual private servers share a single server. This may cause one to wonder what the difference is between aVPS solution and a shared web host.