[Vince]

If you don't know what it is, don't bother with it and just buy slots from a shared host. Some people like to use a VPS or dedi because it provides total freedom. In a shared host you are locked in a box. You have a SA-MP server with a fixed amount of slots, a fixed IP, a fixed port and a simple control panel. That's it. A VPS or dedi has no such restrictions and it's basically just a Linux installation that you can configure to your needs.