官能團(tuán)是決定有機(jī)化合物的化學(xué)性質(zhì)的原子或原子團(tuán),Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.基團(tuán)則不一定決定化學(xué)性質(zhì).但實(shí)際運(yùn)用中,似乎functional group,group,moiety常常是指一個(gè)意思.
烷基是比較特殊的基團(tuán),因?yàn)橥榛荒軟Q定有機(jī)物的化學(xué)性質(zhì),所以不是官能團(tuán),但其它烴基,如：烯烴基,炔烴基,苯基等則屬于官能團(tuán).