The computer is regarded as a hierarchy of levels , each one performing some well - defined functions from the device level ( hardware ) to the problem - oriented language level 計算機被認(rèn)為是分成對個層次,每個層次執(zhí)行某些嚴(yán)格定義的功能,這些功能從設(shè)備級(硬件)到面向問題的語言層次。