The username and password field are never inherited. You can rename a user by typing in a different username here. The generate random password will make a new random password. The length of the random password is defined in the server prefs, encryption tab. You can set other parameters such as special characters, required numbers, and more.

Auto set password on next login will let the user use any password, and the next time they login, that password will be saved to their account for all future logins.

The email, firstname, and last name are useful settings when configuring events. The email is also used here for when they forget their password.

The VFS configures all file access. This is very important!