Learning how to set up a VPS after upgrading from shared hosting is like leaving the kiddie pool to dive into an Olympic-sized one. You have a lot more room and features to play with, but you’ll need to find your footing before you can start having fun. Now that you know how to configure your VPS, you’ve become acquainted with the command line, which will make it a lot easier to set everything up to your liking.
A VPS doesn’t just have more RAM, disk space, and a  proprietary share of CPU than a shared account. Depending on the provider, some VPS plans offer burstable memory, which is a pool of RAM set aside for extraordinary events. This is the stuff that can help counter the so-called “Digg-effect,” that much-whispered about occurrence that’s the simultaneous hope and fear of everyone who runs a web site. When you have an unexpected high traffic event, burstable memory will call on a pool of reserved, shared memory to satisfy the needs of temporary high traffic. This is not available on shared servers and, while the necessary memory is available on a dedicated server, your site might not get the kind of traffic on a daily basis to justify the expense of a dedicated server. Again, not all VPS plans have burstable memory, so ask your provider if their VPS plans do.
So that’s it, then – a VPS is for everything in between, right? Well, yes…and no. A VPS (Virtual Private Server) is a flexible solution that falls in between shared and dedicated hosting, not only in price but also in the way it functions. Like a dedicated server, a site hosted on a VPS gets its own RAM and disk space; however, like a shared server, it uses the same processing capacity (CPU) as a certain number of other sites. So, while your site’s performance isn’t reliant on shared RAM and disk space, it is dependent on a shared processor. Moreover, the distribution of processor share varies from provider to provider.  The table below shows how most hosting companies break down the differences between shared, VPS, and dedicated hosting plans: