Alt text is a piece of text or a word inserted as an attribute in HTML. The role of alt text is to describe an image in order to help crawlers and screen-reading tools describe the image to search engine crawlers or visually impaired readers.
Alt text (alternative text), also known as "alt tag", "alt attribute" or "alt description," is a piece of text or a word inserted as an attribute into an HTML (Hypertext Markup Language) document to describe the appearance or functionality of an image. This helps screen-reading tools describe images to visually impaired readers and allows search engines to crawl your website better. Within most website editors or content management systems (CMSs), the alt-text can be added by simply clicking on the image that was inserted in the blog post or site. There is a field to add the image alt-text, and it is automatically written into the webpage's HTML source code as well, so you can edit the alt-text at any time.
Adding alt text to your website's images helps: