A webring is a collection of websites linked together in a circular structure. Each site connects to the next and previous sites, forming an endless loop of discovery.
Click "Next" on any member site and you'll travel to another site in the ring. Keep clicking and eventually you'll return to where you started, having discovered dozens of interesting sites along the way.
Webrings were popular in the early web (1990s–2000s) before search engines dominated discovery. Today, they're making a comeback as people seek alternatives to algorithm-driven content.