Through the night, people alternate between passive and active sleep. The cycle is repeated several times throughout the night.

整晚我们都在主动睡眠和被动睡眠之间转换。这个循环一晚上要重复好几次。

There are two kinds of sleep, active sleep and passive sleep. The passive sleep gives our body the rest that is needed, and prepares us for active sleep in which dreaming occurs.

主动睡眠和被动睡眠。被动睡眠可以让我们的身体得到所需要的休息，并且为我们进入主动睡眠做好准备。做梦就是在主动睡眠阶段。