charisma_ni_zandro on Nostr: What are Master Fingerprint/s on bluewallet.io? #plebchain? Can someone out there ...

What are Master Fingerprint/s on bluewallet.io?
#plebchain?
Can someone out there gives a brief explanation what's it for?
No need to be technical will be greatly appreciated?
:)
And kindly give example/s if possible?