The act of observing or checking the progress or quality of something over a period of time.

निगरानी

English Usage: The monitoring of air quality is essential for public health.

Hindi Usage: वायु गुणवत्ता की निगरानी सार्वजनिक स्वास्थ्य के लिए आवश्यक है।

To observe and check the progress or quality of something over a period of time.

निगरानी रखना

English Usage: The teacher will monitor the students during the exam.

Hindi Usage: शिक्षक परीक्षा के दौरान छात्रों की निगरानी रखेंगे।