Can someone tell me if I have understood this correctly: A public key thumb print is a hash of the public key. It useful because it is easy to manually validat

Can someone tell me if I have understood this correctly: A public key thumb print is a hash of the public key. It useful because it is easy to manually validate. Edit: when would I need to manually validate? I'm guessing it is used as an identifier when configuring a deployment for a system to a particular environment, for example?