出入

出入 refers to the act of entering and exiting a place, or the movement in and out of a space. It is often used in contexts such as security, access control, or daily routines.

The character 出 (chū) means 'to go out' or 'exit,' while 入 (rù) means 'to go in' or 'enter.' Together, they form a compound that emphasizes the dual action of moving between two states—inside and outside.

出入 is commonly seen in official or formal settings, such as in buildings with security checkpoints, or in descriptions of people’s movements. It can also be used metaphorically, such as in discussions about social mobility or cultural exchange.