监视 (jiān shì): to monitor; to keep a close watch over; surveillance

To prevent confidential documents from leaking, the company installed monitoring software on every office computer to record all employee operations.

The police staked out outside the suspect's residence for three days, monitoring his every move around the clock, and finally waited until he left the house to meet with an accomplice.

The doctor closely monitors the patient's heartbeat and blood pressure changes through a monitor, and once an abnormality occurs, emergency measures are taken immediately.

Meteorological satellites monitor the movement of Earth's atmosphere from space, helping scientists predict the paths of typhoons and heavy rain in advance.

The residential property management installed cameras in the elevators and hallways to monitor the security of public areas around the clock, making residents feel more at ease.