WAI-ARIA provides roles, states, and properties that can be added to HTML and dynamic content with JavaScript to make it more accessible to assistive technologies like screen readers, as it allows things like widgets, dynamic content, and interactive elements to be understood out of context. It includes roles for common interface elements, document structures, and landmarks to aid navigation, as well as states, properties, and other attributes to describe objects and make content more accessible when used properly. The document outlines the problem WAI-ARIA solves, provides examples of its usage, and recommends resources for further information.