ARIA (Accessible Rich Internet Applications) defines ways to make web content more accessible to people with disabilities, especially dynamic content and advanced UI controls. It provides roles, states, and properties that assistive technologies like screen readers use to convey meaning and interactivity. Proper ARIA usage ensures compliance with WCAG and improves the user experience for everyone.

Use native HTML elements whenever possible (e.g., <label> for form controls). For custom elements, add aria-label or reference a visible text via aria-labelledby. Avoid empty labels and placeholder-only inputs. Always test with a screen reader to ensure the accessible name is announced correctly.

aria-label provides a flat string that overrides the element's native label. aria-labelledby references the IDs of other elements whose text content becomes the label. Use aria-labelledby when you already have visible text; prefer it over aria-label because it keeps the label visible and maintainable.

No, you should never apply aria-hidden="true" to a focusable element (or its ancestor) while it is in the tab order. It hides the element from assistive technology but still allows keyboard focus, creating a confusing experience. Remove the element from the DOM or use display:none / visibility:hidden instead if you want to hide it completely.

Redundant roles occur when you add role="button" to a <button> or role="link" to an <a href>. They repeat the default semantics and add no value. Removing them reduces code noise, avoids potential conflicts, and follows the ARIA best practice: "Don't override native semantics unless necessary."