Virtual Private Server hosting, aka VPS hosting, is a website hosting environment that allows for resources such as RAM and CPU to be dedicated to your account. This is achieved by virtualizing a Dedicated server and splitting the resources amongst the users on that server.
VPS hosting gives you high performance with an isolated environment where the CPU, RAM and storage is 100% dedicated and not shared with any other websites or apps. That, compared to shared hosting, results in higher performance and security along with more flexibility and control over the server.