Users generate their own RSA Keys: pgp -kg
A key can have a number of userIDs associated with it. This is the user-printable owner of the key. A key is referenced by its userID, or its keyID (the low-order bits of the Public Key).
pgp -kvv warlord pub 709/C1B06AF1 1992/09/25 Derek Atkins <warlord@MIT.EDU> sig 23BDC6F9 William J. Clinton <email@example.com> sig DE09D78D Albert Gore <firstname.lastname@example.org>
Other users can sign the key, once they have verified it. A signature is a binding between key (ID 0xC1B06AF1) and userID (<warlord@MIT.EDU>).