There are basically two types of Web site: Business or Personal. It's what's on the site that gives it personality and makes it unique. This page discusses some of the potential options.
Personal Web sites can have just a few pages, or they can have blogs, photo galleries, content managers, even online stores. Or they can have all of this.
Business Web sites are the same as personal sites. They can have all the same things: blogs, content, photo galleries, online stores, etc.
In fact, frankly there's a blur between what is a Personal Web site and waht is a Business Web site, since they can both function precisely the same way.
Content management systems are tools that allow you to work on the publishing part of a Web site easily manage a site right online with no special skills or knowledge necessary
One type of conent management system is called, oddly enough, a content management system! Another type is called a "blog" which is short for "weblog" and basically amounts to an online journal.
An interactive option is a bulletin board, also sometimes called a discussion board. You can usually ad users to content managers and blogs to make them interactive as well.
As you can see, we have other cool options like classified ads, online auctions, online stores, and photo galleries, just to name a few.