VPS Hosting is website hosting on Virtual Private Servers. Hosting websites on virtual private servers is (typically) considered to be better than hosting websites on shared web servers. Even though yo0u are still (technically) sharing a web server with other websites, the resources are strictly allocated so that no other website is able to use your set amount of resources.
Think of hosting comparatively like a swimming pool.
On a shared web hosting server, there are a lot of swimmers (with “swimmers” being other websites and the visitors to those websites), and because there are a lot of websites sharing the same web server, there are alot of waves crashing around. The "waves" of the pool are comparative to the web servers resources. Which means, there a lot of resources (on a particular server) in use by a lot of websites at the same time. If the pool (or web server) is overcrowded, the pool has too many waves and slows swimmers way down.
We do not ever oversell our servers. This helps to ensure that all of the websites on our servers are not getting bogged down by a lack of server resources.
We have found that other hosting companies tend to have way too many websites on their web servers and that’s when you have the website performance issues and downtime. If a website is loading too slow or has issues, people will get out of the pool (or leave your website). On a VPS, there is only you (only your website) in the pool and it has ALL of the dedicated resources allocated to it so the waves are very minimal and are only utilized by your website and the traffic that comes to it. The boundaries, on a virtual private server, enforce the resources and don't let other websites use your allocated resources.