What is the purpose of the <a> tag in HTML?

The purpose of the <a> tag in HTML is to create a hyperlink. This tag is essential for linking to other web pages, sections within the same page, or even external resources such as documents or other online content. When a user clicks on the text enclosed within the <a> tag, it redirects them to the linked resource specified in the href attribute. This functionality is critical for web navigation, allowing users to easily move between different sections of a website or discover new sites.

The other options focus on different aspects of HTML. For instance, creating a paragraph is accomplished with the <p> tag, defining an image is done with the <img> tag, and formatting text involves tags like <b> for bold or <i> for italic. Each of these has a specific function that contributes to the overall structure and presentation of web content, but none serve the primary role of creating hyperlinks like the <a> tag does.