1, the frequency of the driving force is equal to the natural frequency of the vibration system.

2. The vibration system needs at least two energy forms that can be converted with each other, one for temporary energy storage and the other for receiving driving energy.

3. In the process of two kinds of energy conversion, the loss of vibration system is not great.

4. The frequency of driving force is equal to the natural frequency of the object. This is a necessary condition for resonance. When the frequency of the driving force is equal to the natural frequency of the object, the amplitude of the vibrating object is the largest. This phenomenon is called resonance.

5. The action point of the driving force should coincide with the action point of the natural frequency of the object.

Types of resonance:

1. Mechanical resonance: When the vibration system is subjected to external force with the same or similar natural frequency, its amplitude gradually increases. For example, jumping off a bridge, shaking a car engine, etc.

2. Acoustic resonance: In a closed space, sound waves may overlap with themselves when reflected, leading to resonance. For example, the acoustic resonance effect of speakers, concert halls, caves and other places.

3. Electromagnetic resonance: In an electromagnetic oscillation system, when the external electromagnetic wave is the same as or close to the natural frequency of the system, resonance will occur. For example, radio and television signal reception, magnetic resonance imaging (MRI), etc.

4. Optical resonance: In an optical system, when the frequency of the external light source is the same as or close to the natural frequency of the system, resonance will occur. Such as laser and optical fiber communication.

5. Molecular resonance: When a molecule is subjected to external energy with a specific frequency, resonance will occur.