Subhan Allah is an Arabic phrase that Muslims use to praise and glorify Allah or God. It is an expression used to recognize the greatness, majesty, and perfection of Allah. Subhan Allah is made up of two words- "subhan" meaning "glory be to" and "Allah" meaning "God".
So, when a Muslim says "Subhan Allah", they are acknowledging the supremacy of God and acknowledging that Allah is far more powerful and glorious than any human being, creature, or object one can imagine. Muslims use it to show their respect and devotion towards Him.
It is a way of praising Allah and seeking His blessings during daily activities like prayer, reading Quran, or performing other religious rituals. Additionally, Muslims say Subhan Allah when they see or experience something that leaves them in awe of God's creation.
In short, Subhan Allah is a way of showing gratitude and appreciation for the wonderful things that Allah has created and for His infinite grace and mercy.