What does the alt attribute in the <img> tag do?

The alt attribute in the tag primarily serves the function of providing alternative text for an image if it cannot be displayed. This is particularly important for accessibility purposes; screen readers use the alt text to describe the image to visually impaired users, ensuring they understand the content of the webpage. Additionally, if the image fails to load due to network issues or other problems, the alt text will be displayed in its place, maintaining context for users.

This attribute enhances user experience and promotes inclusivity, as it caters to a wider audience by providing essential information that would otherwise be inaccessible in the absence of the visual element. It does not specify hover text, size, or link to another image, which are functionalities tied to other attributes or elements in HTML.