However, if a bad user shares your server with you, they can threaten your security and allow hackers to easily reach your content and critical data. Furthermore, because you’re all sharing the same resources, if any of the users that you’re sharing your server with use a lot of memory or their site has a lot of traffic, your website’s performance is likely to suffer.

Simply put, shared hosting means your site will share the same server as many other sites. It’s usually the cheapest option but comes with limited bandwidth, administration, and performance capabilities. VPS hosting is a more premium option, with the ability for greater customization and increased performance. But, as with any premium service, you’ll have to pay more to get more.
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.