从词性来看,far既可以做形容词,又可以做副词；away 只能做副词.
从用法来看,far 不能跟具体数字连用.有时far 可以和away 连用.
eg.My home is not far from my school.
My home is two kilometers away from my school.
My home is far away from my school.
希望能帮到你,祝你开心.