To be able to access a MySQL database you must first create a MySQL user.
Once the user has been created, that user can be assigned different access rights to different databases.
This can also allow you to grant access by multiple users with different rights to some or all of your databases.
This demonstration shows how to create a MySQL user.
Enter the username you wish to use for this user
(this is restricted in length to 16 characters, after being prefixed by your username and an underscore_.
If you enter a username beyond this limit it will be truncated),