VPS ensures that your website continues to run smoothly, regardless of what is happening elsewhere on the server. It also protects your data from multiple sites, giving you a secure piece of virtual real estate to build a website on.
VPS hosting is like you are living in an apartment complex. It means that other people are living in the same building, but you have your own secure apartment. You will get more room and restrictions will be fewer as compared to living in a dorm. It also means that if your neighbour is misbehaving, it is the problem of owner of building, not yours.
As you can see, a VPS can be the perfect middle ground for many – enough flexibility and resources for those who need more access or control than on a shared server but without the cost of a dedicated server. If you need root access, you can’t get that on a shared server, but you can get it on a VPS. If your site experiences unpredictable swings memory usage, and your host provides it, then the presence of burstable memory will be attractive. And, if you’re a fan of customization, then the fact that you can customize server-level software such as PHP, MySQL, and Apache will perk your interest.  In short, choosing a VPS will allow you to have many of the same characteristics of a dedicated server but in a more affordable and manageable package.