Frequency அதிர்வெண்
How many times something repeats each second; in sound, a higher frequency is a higher pitch.
See it in Audio visualizer. Press Microphone, pick Spectrogram and whistle low, then high: the bright line climbs as the frequency rises.
In plain words
Frequency counts how often something repeats in one second. It is measured in hertz, where 1 hertz means once a second. A deep drum shakes the air about 60 times a second, and a whistle a few thousand. People hear from about 20 to 20,000 hertz. Pictures have frequency too: fine detail changes quickly across the image, broad shapes change slowly.