In general, this term refers to a period of Japanese history lasting from the 4th century to the 6th century, but it can sometimes refer to a period lasting from after the Yayoi Period to just before the Nara Period, including the Asuka Period (from the latter half of the 6 century to the 7 century).
一般的には4世紀頃から6世紀頃までを指すが、時に飛鳥時代（6世紀後半-7世紀）をも含め、弥生時代の後、奈良時代の前をいうこともある。