An alt attribute, short for “alternative text,” is an HTML attribute used to describe the content of an image on a webpage. It provides textual information about the image for users who cannot see it, such as those using screen readers.

Example:

<img src=”example.jpg” alt=”A woman riding a bicycle through a forest”>

In this example, the alt attribute describes the image as “A woman riding a bicycle through a forest.” This text would be displayed in place of the image if it cannot be loaded or viewed by the user, providing context and information about the image’s content.