Providing alternative text for images is the practice that ensures a textual description is available for assistive technologies to read aloud. When a screen reader encounters an image, it uses the alt text to communicate what the image represents or its function to the user. If the alt text accurately describes the essential content or purpose of the image, someone listening to the description gets a clear sense of what’s shown, even without seeing it. Best practices include writing concise, meaningful alt text that conveys the image’s content or purpose. If the image conveys important information (like a chart or diagram), describe that information in the alt text. If the image is decorative and doesn’t add meaning, the alt attribute should be left empty so screen readers skip it and don’t clutter the reading flow. For images that act as controls (like a button), alt text should describe the action (e.g., “Submit form”) rather than detailing the image itself. Other options touch on different accessibility needs but don’t specifically ensure an image has a textual description for screen readers. Captioning and transcripts relate to text for videos or audio; keyboard navigation focuses on moving through interactive elements with a keyboard; and screen-reader-friendly structure covers overall semantic organization, not the dedicated description of each image.