1, What's the difference between PGP and GPG?
PGP stands for Pretty Good Privacy and it's an encryption program. It is used for signing, verifying, encrypting, decrypting e-mails, files or whole disk partitions. An open standard of PGP encryption is OpenPGP.GPG stands for GNU Privacy Guard and it's an open-source software that replaces the PGP's cryptographic suite. It is part of the OpenPGP and uses a combination of conventional symmetric-key cryptography for speed and public key cryptography for ease of the keys' exchange.
2, What is a PGP fingerprint used for?
For identification. You'll upload your fingerprint to a server along with your public key and if someone ever wants to search you, they'll just use the fingerprint to claim the whole public key.3, What things can I share in PGP? (Fingerprint, Key ID, Public Key, etc...)
A key ID and a fingerprint is the same thing. I can't think of another thing you can share in PGP if we exclude encrypted/signed messages. 4, Is there any other important thing that I need to know about PGP?
It depends on your character. If you're a person who wants to “dig” the technical stuff and understand how they work, then you'll have to deal with the maths behind the symmetric-key cryptography used in PGP.PGP is can be cracked. Additional info in google.
Why don't you leave an article that explains it provably? 
