opening / the Opening (first surah)
Active participle (feminine) of فَتَحَ (to open). السَّبْعُ المَثَانِي (the seven oft-repeated) is another name for al-Fātiḥah. Also called أُمُّ الكِتَاب (Mother of the Book).
Al-Fātiḥah is recited in every unit of every prayer - a Muslim who prays five daily prayers recites it at least 17 times a day. It is the most recited chapter in human history.