Meaning : Morally or legally constraining or binding.
Example :
Attendance is obligatory.
An obligatory contribution.
Possible but not necessary. Left to personal choice.
optionalMeaning : Required by obligation or compulsion or convention.
Example :
He made all the obligatory apologies.
Obligatory ka meaning, vilom shabd, paryayvachi aur samanarthi shabd in Marathi. Obligatory ka matlab kya hota hai?