Thanks. Found it.
Now what can I do with it?
The primary purpose is for drive encryption. I have an encrypted partition on my hard drive to which I save personal data such as bank statements, pay stubs, tax documents, etc. I also have my Firefox profile pointed to it, so if the Feds wanted to see where I’ve been browsing from my hard drive, they’d have to decrypt it first.
You can also use it to generate self-signed certificates for email non-repudiation and signing.