http://y7yea4pmqqtznb33qiugvysyn2bob5v62e4pvoadoibrwkq3tsddjeyd.onion/zh-hans/glossary/fingerprint
A fingerprint is a much smaller number or set of numbers and letters that can be used as a unique name for that key , without having to list all of the key's digits. So, for instance, if you and a friend wished to make sure you both had the same key, you could either spend a long time reading off all the hundreds of digits in the key, or you could each compare your key's fingerprints instead.