Which tag is used to define a paragraph in HTML?

The tag used to define a paragraph in HTML is the P tag. This tag specifically indicates a block of text that is meant to be read as a paragraph, providing a structural element in web documents. When content is enclosed within the P tags, it is typically rendered with spacing above and below the text, allowing for easier reading and better presentation on a webpage.

The P tag also has semantic significance; it signifies that the enclosed text is a standalone paragraph, which aids in both accessibility and search engine optimization. This is crucial for enhancing the user experience by helping browsers and assistive technologies understand the organization of your content.

Other tags like the Div tag, Span tag, and Header tag serve different purposes. The Div tag is used for grouping larger chunks of HTML elements, the Span tag is typically used for inline styling or grouping text within a paragraph, and the Header tag denotes headings, which help to organize content hierarchically. Thus, the P tag is uniquely suited for defining paragraphs in HTML.