Hi Marco,
it is possible to manage several key-pairs and identities in one installation.
(Technically the key-pairs are kept in the crypto engine, which is GnuPG. The selection which key-pair to use, is a combination of the frontend and the crypto engine and their configurations.)
To be able to use a key-pair on a different machine, you need to export the the private key from the first machine, transfer it and import it again on the second machine. Also with the corresponding public key, but the secret key
is the more important part of the operation.
It is a common usage that “functional” OpenPGP key-pairs are used, and thus one public key is distributed to several communication partners for encryption (or for checking a signature).
“Functional” means that the key-pair belongs to a group, and usually with an email address that marks this like security-team@example.com.
(Naturally, the handling of the key-pair, especially the private key, needs operational guidelines in the organisation.)
Best Regards,
Bernhard