A server is just a computer.
Okay so its not just any computer. Its a powerful computer which should (hopefully 🤞) always be on and which many other machines on the same network can connect to - like your laptop or your desktop. Various data can be stored on a server, and different tasks and processes can be performed on it. Think of it as a brain where different body parts can access things stored in a brain and the brain can also tell the body parts what to do.
There are different types of servers for different purposes, including:
- Application server: This is most familiar to me. The code which powers an application is stored on the server, and any machine using the application will send requests to the server, which will send back a response. Each button in an application will send a different message, and the request which is returned determines what happens after clicking the button.
- Database server: This is where different databases are stored and managed. Examples include Microsoft SQL Server and Snowflake.
- Game server: If you've played a multiplayer game, you've accessed a game server. Let's think about Minecraft - different people can access the server and play the same game together. The server hosts all of this.
Servers can be physical - actual computers which are located in an organisations building - or can be cloud based - hosted by a third party and accessed online.
- Some organisations may need to comply to certain rules, e,g., finance organisations handle sensitive data and therefore must be managed on site. For this you need on premise.
- All servers require maintenance to ensure they remain on and usable. If you have an on premise server, you need to perform this maintenance yourself (which can be advantageous), but using a cloud server essentially outsources the maintenance to the cloud provider.
- There are cases where a server may need to be made bigger or smaller quickly, or may even not be used at all times. Cloud servers can be scaled up or down at any time, but on prem is one fixed size. Using a cloud server can save an organisation money as they are only paying for the resource they require.
- For complete control of the server and the data stored on it, on premise servers are the way to go. With a cloud server you give up some of that control to the provider.
I think about cloud vs on premise like real estate. An on premise server is like owning your own house. Its yours to keep, you are responsible for making sure the doors are locked and you have to clean up after yourself. A cloud server is like renting a place. Your landlord owns the property and you're just borrowing it (in exchange for money). Its the landlords reponsibility to fix the leaky taps and you can move out without much hassle when you're ready to leave.