Every image in a web application must be categorized for assistive technology under WCAG 1.1.1:
Images that convey conceptual information, instruction, or data (e.g., an infographic or a photo demonstrating how to wear a headset).
alt text explaining the content and functional purpose to screen reader users.Images used purely for visual styling, emotional ambience, or redundant decoration (e.g., a background flourish).
alt="") or aria-hidden="true" so screen readers ignore them rather than reading irrelevant filenames.Level 2 · Elements of Design I