Someone who is unconscious is in a state similar to sleep, usually as the result of a serious injury or a lack of oxygen.
By the time the ambulance arrived he was unconscious.
救护车赶到时他已神志不清。
If you are unconscious of something, you are unaware of it.
oblivious
He himself seemed totally unconscious of his failure.
他本人似乎完全没意识到自己的失败。
If feelings or attitudes are unconscious, you are not aware that you have them, but they show in the way that you behave.
my unconscious ambivalence about becoming a mother.
我无意中显示出的对于成为一名母亲的矛盾心理。