What does CMS stand for?
CMS stands for Content Management System.
There are many types bundled into this term some you pay for some you are free. Websites tend to be based on CMS products these days and you can download for free a full working web site. It may not forefil all your needs but it is a starting point. From this you can develop the site for all the services you want to give to your users.
Some common CMS products are: