What is a website? You can ask any n00b that question and they'll tell you a website is what loads when you go to a name.domain. Although, that is stupidly vague, it is right. However that as far as most these n00bs go to understand. I see a website as being described between two different labels. Community Driven vs. Information Portal.
Community Driven is defined by scope of design emphasis on users visiting and/or signing up to interact only with other users.
Information Portal is defined by scope of design emphasis on users visiting and/or signing up to get information.
The most successful community driven websites are ones that have zero personality within their design and functionality, or even depend on the community to create one for them. The most successful information portals are ones that have the most personal emphasis within their designs and functionality.
Take wikipedia for example. It falls furthest on the information portal end of the spectrum because the site main focus, which is proven so by its design, of the website is the content within the site which is above the interactions of the editors. However, every single website can benefit from having some level of community interaction, which is why wikipedia is increasing community involvement functionality with discussion boards.
The main idea though is to really hone in on what you're trying to accomplish with your website and find the balance of community involvement to achieve your goals with your website. This is where design comes in, because depending on the scope of your website would determine the emphasis of certain functions of your website.