Many times you want to link from your web page to an external source or related page, but you have multiple such sources or related pages connected to the same word or phrase.
Optimally this might be built into the needed protocols, but currently, it can be accomplished using JavaScript. When clicking you will get a small popup menu with all the links and their separate anchor texts and you can choose which one to follow. These are actual multiple hypertext tags, just hidden until you click on the visible one. This will enable search engines also to crawl all linked URLs.
If you publish articles and posts on your own, you want to enhance them with an image, a photo or an icon. It’s tedious and time-consuming to search for the right image with the right license.
Have a search engine that takes text or a URL of a web page, and based on that text find you the right images with the right license (probably some version of Creative Commons.)