Database

Hello,
I apologize for the dumb question, but I am a total beginner… I have to modify the file wp-config, but I am not sure about:

define(‘DB_NAME’, ‘putyourdbnamehere’); // The name of the database

What database?

define(‘DB_USER’, ‘usernamehere’); // Your MySQL username

what username?

I am not sure that I understand what and where the database is.
Can anyone help me with that?
Thanks!