A shared web hosting account is an account on a web server that hosts other shared accounts. The number of accounts on one shared server can vary widely; some servers host a few hundred, while others have thousands of sites hosted on one server. Hosting your website on a shared server is a workable solution for many small businesses, as shared hosting accounts are priced much lower than dedicated servers. Shared web hosting accounts have limited access to the core administrative functions of the server. Most web hosting companies offer comprehensive technical support for users of shared hosting plans. Complete technical support is usually included in the price of your account plan. 

A dedicated server is usually dedicated to one, or just a few websites, usually for the sole use by one company. The cost of a dedicated server is higher than that of a shared hosting account. With a dedicated server, you have access to the core administrative functions of the server. With most dedicated server plans offered by hosting companies, youre pretty much on your own where technical support is concerned. If you dont have an IT staff or a server administrator to provide support, you may want to find a person to help you manage your dedicated server. Many hosting companies that offer dedicated server plans also offer "per issue" support, meaning that youll pay a certain amount, usually an hourly fee, for technical support issues. Some dedicated server plans have optional "support tickets" that you can purchase in advance. 

Another option is whats called a "managed dedicated" hosting plan. With a managed dedicated plan, you get a dedicated server and the hosting company also provides comprehensive support like you usually find in a shared hosting plan. This is a good alternative for companies that dont have an IT staff or a server administrator and dont want to get involved at all in the technical aspects of running a server. The price for a managed dedicated server is usually higher than for an unmanaged dedicated getting technical support included. Server plan as youre getting technical support included. 

A virtual dedicated server lets you run your sites as if you had your own "dedicated" server, except it is cheaper because you are really just using part of a server that has been split into multiple virtual dedicated servers. You can get a much larger bandwidth compared to shared hosting, and none of the problems that go with a shared host. You can also get multiple IP addresses that are exclusive to your sites. 

You need to probably spend a bit more on hosting each month. The main disadvantage of upgrading to virtual dedicated hosting is that you will need to be more technically proficient so that you can administer the server. This requires a bit of time learning the necessary Linux skills to make sure your server runs smoothly. 

Many hosting providers will have a "premium" support offering that includes a bit more hand holding - this is definitely recommended if you dont have much experience with Linux, or are new to virtual dedicated hosting.