Web sites, or web site, according to Associated Press guidelines, is a collection of web pages, typically common to a particular domain name or subdomain on the World Wide Web on the Internet.

A web page is an HTML/XHTML document that is almost always accessible via HTTP. All publicly accessible web sites are seen as constituting a gigantic "World Wide Web" of information. The pages of a web site will be accessed from a common root URL called the homepage, and usually reside on the same physical server. The URLs of the pages organise them into a hierarchy, although the hyperlinks between them control how the reader perceives the overall structure and how the traffic flows between the different parts of the sites.

Some web sites require a subscription to access some or all of their content. Examples of subscription sites include many Internet porn sites, parts of many news sites, gaming sites, message boards, Web-based e-mail services and sites providing real-time stock market data.

Web sites may be the work of an individual, a business or other organization and are typically dedicated to some particular topic or purpose. Any web site can contain a hyperlink to any other web sites, so the distinction between individual sites, as perceived by the user, may sometimes be blurred.

A web site is written in, or dynamically converted to, HTML (Hyper Text Markup Language) and is accessed using a software program called a web browser, also known as a HTTP client. Web pages can be seen or otherwise accessed from a range of computer based and Internet enabled devices of various sizes, examples of which include desktop computers, laptop computers, PDAs and cell phones.

Web sites are hosted on a computer system known as a web server, also called an HTTP server, and these terms can also refer to the software that runs on these system and that retrieves and delivers the web pages in response to requests from the web site users.

“Apache” is the most commonly used web server software according to Netcraft statistics and Microsoft's Internet Information Server (IIS) is also commonly used.

A dynamic web site is one that has frequently changing information or interacts with the user from various methods (HTTP cookies or database variables e.g., previous history, session variables, server side variables, e.g., environmental data, etc.) or direct interaction form elements, mouseovers, etc.