Documentation - Unattended
This page is useful in automating the installation process so that you do not have to be in front of your computer while it is installing. Options are pretty self-explanatory.
Skip user creation - can be used to skip OOBE on the first logon which asks you for the first user name. Instead it will logon as a built-in Administrator.
Regional - useful in setting the GUI language (you can choose integrated Language packs) and to set options which are usually presented in the first popup on ISO boot.