This is the 2614th most frequent Chinese word.
身后
"身后" means "behind the body" or "after one's death."
In this sentence, '身后' is used metaphorically to refer to 'after one's time or affairs after someone leaves'.
他走了,我常常想着他的身后事。
He left, and I often think about his affairs after departure.
Here, '身后' is used literally to indicate 'behind someone' in terms of position.
他站在我的身后,好像在等待什么。
He stood behind me, seemingly waiting for something.
In this usage, '身后' denotes a spatial relation, specifying the location relative to one's back or journey.