after与behind两者均可表示“在……之后”，其区别是：
1、after 主要用于时间或次序，behind 主要用于位置。
如：
He decided to leave after lunch. 他决定午饭后离开。
Summer comes after spring. 春去夏来。
The hospital is behind the post office. 医院在邮局后面。
注：behind 有时也用于时间，表示“迟于”，主要用于 behind time(迟，晚)这一习语。
如：
The train was 20 minutes behind time. 火车晚点 20 分钟。
2、两者都可用于引申义，after 侧重指追求、寻找、模仿等；而behind 则侧重指在背后、支持、落后等。
如：
The police are after her. 警察在追捕她。
Many young people are after her. 许多年青人都追求她。
We are behind you completely. 我们完全支持你。
He is behind the others in maths. 他的数学不如别人。
但表示随手关门时，after 和 behind 都可以用，没什么区别：
Shut the door after [behind] you. 请随手关门。
Shut the door after [behind] you when you go out. 出去时请随手关门。
She went out, shutting the door after [behind] her. 她走出去，随手关上门。
I walked out and closed the door after [behind] me. 我走了出来，随手带上了门。
He banged the front door after [behind] him as he left. 他走的时候砰的一声关上了前门。
Wade stepped inside and closed the inner door after [behind] him. 韦德走进去，随手带上了里面的门。
He reminded her that he would have to lock and bolt the kitchen door after [behind] her. 他提醒她，在她走后他得把厨房的门上锁并闩上。