Resonance is a phenomenon in which the amplitude increases at a specific frequency.
The resonance phenomenon can be easily observed around us.

1. Swing
When you push the swing, if you push it well according to the swinging cycle, the swing swings well. On the other hand, regardless of the movement of the swing, the swing does not swing well if it shakes wildly.

2. Radio, TV
Tuning a radio frequency or TV channel to receive a broadcasting device is the process of matching the internal frequency of the radio or TV with the frequency of the electromagnetic wave of the broadcasting station. Other frequencies that do not resonate in this process are automatically filtered out and disappeared.

3. Microwave
When you put food in a microwave oven and operate it, an electromagnetic wave that matches the vibration frequency of the water molecules vibrates the water molecules and increases the food's temperature.

4. Another example of a resonance phenomenon is that a wine glass held by an opera singer who can speak loudly in a high-pitched range vibrates and breaks itself when it matches the song's frequency.