Shared hosting is great for informational sites and new websites that don’t immediately have a ton of traffic. The pros are that it is very inexpensive compared to other options, but the cons are that your website is on a shared server with hundreds or thousands of other websites and their performance could adversely affect your own.
A VPS or Virtual Private Server share one physical server but act like multiple and separate servers. It’s usually the option most business sign up for when they have a lot of web traffic and/or sell products in which having there website load slow, or go down, can greatly impact revenue. Pros: more CPU and RAM than shared, but costs a bit more.
A dedicated server means renting a physical server that you have full control over. This is for company’s with massive incoming traffic and that don’t want to worry about shared websites taking up resources and slowing down there own website. The price is a lot higher than shared or VPN and you usually want to hire a system administrator to take care of any technical details.