Which characteristic specifically describes a markup language?

A markup language is characterized by the use of tags that surround text to describe how that text should be structured and formatted. These tags define the elements of the document, such as headings, paragraphs, links, and images, allowing for the organization and presentation of content in a way that is both meaningful and visually appealing when rendered by a browser or viewer.

The presence of these tags is fundamental to how markup languages function. For example, in HTML (HyperText Markup Language), elements such as <h1>, <p>, and <a> are tags that specifically dictate the formatting and structure of the content within a webpage. This allows users to create rich, structured documents that adhere to specific formatting rules as dictated by the markup language being used.

In contrast, the other options discussed do not accurately describe the defining characteristics of a markup language. The second option pertains more to programming logic, where output and variables are defined, rather than to markup and structure. The third and fourth options relate to the operations of compilers and interpreters, which are concepts relevant to programming languages rather than markup languages. Therefore, the focus of a markup language is specifically on the formatting descriptions provided by tags, making the correct answer representative of the essence of markup