规范 (guī fàn) as a noun or adjective refers to an established norm or standard that provides guidance, implying something is 'normative' or 'standard.' It contrasts with 规定 (guī dìng), which is a concrete rule or regulation stipulated by an authority, and with 标准 (biāo zhǔn), which is a more measurable criterion for evaluation. As a verb, 规范 means to regulate or standardize something to make it conform to a norm.