What function does the <span> element serve in HTML?

The element in HTML is primarily used to apply styles or scripts to specific portions of text within a block of content. Unlike block-level elements that typically start on a new line and take up the full width available, the element is an inline element. This means it can be used without disrupting the flow of text, allowing developers to style or manipulate individual words or phrases without affecting the surrounding content.

When you want to change the color, font weight, or other CSS properties of specific text within a paragraph without altering the entire block, the element is ideal. For instance, you might want to highlight a particular word or phrase in a sentence or apply a specific animation through JavaScript. This flexibility makes a fundamental tool in web design for handling inline text modifications.

The other options mention functionalities associated with either block-level elements, layout systems, or document metadata, which do not pertain to the primary purpose of the element.