Required for accessibility, alt text is hidden text that helps visually impaired users understand the visual contents on the page via screen reader software.
In the event that an image fails to load, users will instead see the alt text next to the missing image icon. In this way, they still get some context for what the missing image entailed.
Use alt text on any images/icons that add meaning to a page or that link to somewhere. Add alt text (up to 65 characters) to your web page's html within the
alt="" attribute for each image.
As most images/icons are clickable, alt text should include a call to action (CTA)
alt="Find out more about Windows 10" unless the use of a proper noun is more suitable, e.g.