What characteristic defines text documents formatted with HTML?

Text documents formatted with HTML are defined by their role as structured documents used for web content. HTML, which stands for HyperText Markup Language, is the standard markup language for creating web pages and web applications. This structure allows for the organization and presentation of text, images, links, and other multimedia elements in a way that web browsers can interpret and display.

HTML incorporates various elements that dictate how content should be displayed, such as headings, paragraphs, links, lists, and other semantic tags. This structure not only aids in the visual arrangement of the content on the page but also contributes to the accessibility and search engine optimization of the web document. By using HTML, content can be formatted consistently and made navigable, providing a coherent user experience.

The focus on structured content in HTML sets it apart from document types that prioritize images or serve different functions, such as simulations or direct server communication. As a result, recognizing HTML's role in formatting web content is fundamental to understanding how the web functions.