In order to decrypt messages intended for you, or sign things so others know it came from you (like git commits) you'll need a GPG key.
Although you can create a GPG key from the computer you're using to read this, you probably shouldn't. Computers you use to browse the Internet can get malware/viruses, and those can read any file on your computer. It's safest to work with private keys (both GPG keys and cryptocurrency private keys) on another machine that is airgapped.
➡️ Learn how to set up an airgapped computer here ⬅️
<aside> 💡 It is recommended that all work performed on raw private keys is always done on an airgapped machine.
</aside>
GPG Keys have 4 capabilities:
GPG Keys can also have multiple child keys (which each have their own capabilities), and multiple user IDs (a User ID is a pair of "Full Name" and <email address>)
Yubikeys can store 3 GPG keys: one for encryption, authentication, and signing.
New Yubikeys come from the factory with the following default PINs:
12345678123456certify and sign capabilitiesencryption, authentication, and signing.