Alt Attributes
Alt attributes make it possible to enter an alternative description in the HTML code for every image on a website.
This description appears if, for some reason, the image cannot be displayed. Search engines’ ability to recognize the contents of images is still limited which is why they rely on the alternative description in order to determine what the image contains. The alt attribute can influence the content for which search engines consider a website to be relevant. Ideally the alternative descriptions should also contain the search terms for which the website is optimized.