Number of rak‘ahs in voluntary prayers

Al Liwaa:  Are the prayers performed before and after the five daily prayers obligatory or voluntary? How many rak‘ahs are they, and when are they performed? - The prayers performed before or after the five obligatory prayers are either confirmed Sunnah prayers, which the Messenger of God, peace and blessings be upon him, regularly observed, and which are mentioned in the noble hadith: “Whoever…”