Organised by function a website is for a business or other organisation and is typically dedicated to some particular topic or purpose.

A Web site is a related collection of files that includes a beginning file called a home page. A company or an individual tells you how to get to their Web Site by giving you the address of their home page. From the home page, you can get to all the other pages on their site.

A synonym and less frequently used term for Web site is "Web presence." That term seems to better express the idea that a site is not tied to specific geographic location, but is "somewhere in cyberspace." However, "Web site" seems to be used much more frequently.