Meaning
A name that means something.
H"Handsome, good, excellent." Name of the Prophet's eldest grandson, son of Ali and Fatima — remembered for his gentleness and restraint.
Etymology, in one line
Arabic root: ḥ-s-n — ح-س-ن, beauty, goodness
Regional variants
"Hasan" is the classical spelling; "Hassan" is more common in US transliteration (matches the intuitive English reading). Royal name in Morocco (Hassan II) and Jordan.