At a minimum, please enter first and last name. You can enter anything you like, but here is what Willow does with the information:

The first name is the actual first name of the user, such as Robert, known as the "given" or "christian" name in the West.

The nickname is what the user prefers to be called, such as Bob.

If you do not specify a first name, then the nickname is used as the first name. If you do not specify a nickname, then the first name is used as the nickname. You do not have to specify either, but you should.

The middle names contains any names that are not the first name, nickname, or last name. Enter as many as you like.

The last name contains the family name of the user.