What is the primary use of HTML?

The primary use of HTML, or Hypertext Markup Language, is for creating web pages. HTML provides the fundamental structure of a website and is used to organize content in a way that browsers can interpret and display. It employs a series of elements and tags to define headings, paragraphs, links, images, and other types of content. By structuring web information through HTML, developers can build visually appealing and functionally coherent websites that users can navigate effectively.

The other options, while they relate to functions on the internet, do not pertain to the primary purpose of HTML. Transferring files typically involves protocols such as FTP, securing internet connections relates to encryption methods like SSL/TLS, and sending emails is managed through protocols such as SMTP. Thus, HTML's specific focus on web page creation distinguishes it from these other technologies.