Welcome to Webhosting talk edith. The main difference between VPS hosting and a dedicated server is really the physical component. With a VPS your basically isolated to a section of a server and don't always get the ability to use the full use of the server. What I mean by full use is like making changes to the server kernel and etc. It sounds like most likely a VPS would be something you might want to consider from the little bit of information you have provided.