Buddha's sariras refer to the cremated ashes of Buddha's bones as well as the remains of the coffin and altar that were used for the cremation of Buddha when he passed away.
仏舎利（ぶっしゃり）とは、入滅した釈迦が荼毘に付された際の遺骨及び棺、荼毘祭壇の灰塵を指す。