GPG trying to understand about of public and secret keys

GPG trying to understand about of public and secret keys

Introduction

In SSH can be created a pair of keys as follows for example:

• id_rsa
• id_rsa.pub

Where the first one is the private and the second is the public. Where both:

• Are located in the ~/.ssh directory
• Is possible apply the cat command to see the content of each key

And of course the private key must be never shared. So far I can do a SSH connection in peace

GPG

Exists the ~/.gnupg directory which contains the following files among others:

• pubring.kbx
• openpgp-revocs.d
• private-keys-v1.d

I've confirmed when the following command is executed successfully:

• gpg --full-gen-key

About the output as follows:

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? O
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
gpg: revocation certificate stored as '/home/manueljordan/.gnupg/openpgp-revocs.d/2A49B648C65C5F73C1FD17A2FBCFD538D559606D.rev'
public and secret key created and signed.

pub   rsa3072 2025-02-13 [SC] [expires: 2025-03-15]
      2A49B648C65C5F73C1FD17A2FBCFD538D559606D
uid                      Capitan Futuro (Nave Cometa) <capitanfuturo@gmail.com>
sub   rsa3072 2025-02-13 [E] [expires: 2025-03-15]

Furthermore happens mostly the following:

• The pubring.kbx file is updated
• In the openpgp-revocs.d directory is created the 2A49B648C65C5F73C1FD17A2FBCFD538D559606D.rev file. Here the full fingerprint was applied in the new .rev filename
• In the private-keys-v1.d directory were created two <40-random-characters>.key files

I know that a private key is the same as a secret key. It about terms

Sorry for the following set of questions but because they are tight related I think is wise have all of them together

1. Why was created two private keys in the "private" directory?
2. What is the purpose of each private key?
3. By whom is used each private key?
4. Where is located/stored the public key?

For (1.) is possible apply the cat command and for (4.) the full fingerprint is generated from that public key so the latter must be read it from some place. And I am assuming is possible apply the cat command for the public key too.