Answers for "public ssh key"

get public ssh key

ssh-keygen
cat ~/.ssh/id_rsa.pub

ssh get key

cat ~/.ssh/id_ed25519.pub

what is role of public key in ssh

A public key that is copied to the SSH server(s). 
Anyone with a copy of the public key can encrypt data which 
can then only be read by the person who holds the corresponding private
key.