A virtual private server is a slice of a physical machine, allocated to you alone.
HOW IT WORKS
A physical server runs virtualisation software that divides it into several independent virtual machines. Each has its own operating system, its own allocated CPU, memory and disk, and its own network address.
Your VPS behaves like a separate computer. You can reboot it without affecting anyone else, install what you like, and change any configuration.
HOW IT DIFFERS FROM SHARED HOSTING
On shared hosting you have an account on a server we manage, with limits enforced around you.
On a VPS you have the machine. The resources are reserved for you rather than shared, and nothing another customer does affects your performance.
HOW IT DIFFERS FROM A DEDICATED SERVER
A dedicated server is an entire physical machine. A VPS is a portion of one. For most workloads the difference is cost rather than capability.
WHAT YOU TAKE ON
Responsibility for the operating system, security patching, backups, monitoring and configuration, unless you buy a managed option.
That is the real difference, and it is not small.
