What are the reasons for the revelation of Surat Al-Fatiha and its status, and does it possess a unique characteristic that distinguishes it from others, and why do we begin our prayers with it?

Surat Al-Fatihah is Makki and no specific reason for its revelation has been mentioned. Its status is great because it is the greatest surah in the Quran, a pillar in prayer, the first surah in the Mushaf, and nothing like it has been revealed in any divine book. It includes many lessons, among them: praising and glorifying Allah, affirming His dominion and mercy, and singling Him out for worship and seeking help.