How to generate and backup a gpg keypair on Linux

Gnu Privacy Guard (gpg) is the Gnu project free and open source implementation of the OpenGPG standard. The gpg encryption system is called ?asymmetric? and it is based on public key encryption: we encrypt a document with the public key of a recipient which will be the only one able to decrypt it, since it owns the private key associated with it. Gpg allows us also to sign documents using our private key and let others verify such signature with our public key. In this tutorial we will see how to generate and create a backup of a gpg keypair.