Is it a key or certificate?

An OpenPGP certificate contains a public key, one or more user identities and one or more public subkeys. However, certificates are commonly but mistakenly referred to as keys, like the key servers that really serve certificates. The correct terms are described in RFC4880 and in the PGP book An Introduction to Cryptography which you can find at ( http://bit.ly/2n6Lwmgf).

This misrepresentation is also discussed at http://bit.ly/2nzn7RD.

For this tutorial we’ve kept with common parlance and used “key” throughout the text.