Think of a shared server as a large apartment complex, and all of the individual apartments are rented by other website owners. All of you need a place to live — just like your website’s files — but going out to buy a huge family home would be too expensive for your needs. Sharing common areas and utilities in an apartment block helps keep costs down. And the same is true for shared hosting.
And if your “neighbor” on the server is hacked, there’s little chance the infection will spread to your VPS because the hypervisors that are used to create separate VPS environments deliver multi-layered network security and keep tight controls on what enters and leaves. Your root access also means you can add or customize your VPS security software as you please.
The answer to this question is a definitive “maybe.” Since you’re looking at this site, you might be a Web designer who has a few sites, an online portfolio, and a couple of long-standing clients whose sites you manage. Is a VPS for you? Well, you’ve most likely outgrown a shared platform, and as a professional, it won’t do to have your site run poorly because another site that you share a server with is using more than its fair share of resources. A dedicated server could be overkill – if you don’t need all the resources on a consistent basis, you may not be able to justify the expense.