Wirebook › Glossary › Fragment
What is a fragment?
In one sentence: The part of a URL after #. It stays in your browser and is never sent to the server.
A little more
The fragment is everything after the # in a web address. Browsers use it to jump to a part of a page (like a heading), and web apps use it to remember state. Crucially, the browser never sends the fragment to the server.
That makes it a good hiding place for a secret key: a link can carry the key to your friend, while the server that delivers the page never sees it.
It's a bit like… A sticky tab on a page of a book: it helps you find your place, but you don't post it to the publisher.