Screen readers describes software that allows users to listen to the content on a web page and navigate through a website without needing to view the visual content displayed on a screen. Some common examples are JAWS, NVDA, or VoiceOver.
Screen readers enable using a range of keyboard shortcuts or voice commands to allow users to jump from element to element on the page, take shortcuts to the content that matters most to them, and many other text reading and navigation options.
It’s important when you are developing a website to build in functionality like ARIA labels, landmarks, alt tags, and correct heading structures so that users of screen readers can access the content on your website as effectively as those who do not use screen readers.