While there are many millions of pages that are predominantly composed of HTML, or some variation, in general we view data, applications, E-Services, images (graphics), audio and video files, personal web pages, archived e-mail messages, and many more forms of file and data systems as belonging to websites and web pages.
While there are many hundreds of ways to deliver information on a website, there is a common body of knowledge of search engine optimization that needs to be read as an advisory of ways that anything but text should be delivered. Currently search engines are text based and are one of the common ways people using a browser locate sites of interest.