The tendency of a system to oscillate with greater amplitude at certain frequencies.

This phenomenon is known as resonance. In resonance, the system absorbs more energy when it is subjected to external forces at specific frequencies that match its natural frequency. This causes the system to vibrate with greater amplitude, potentially leading to damage or failure if not controlled. Resonance can occur in mechanical, electrical, and acoustic systems, among others. It is important to understand and mitigate the effects of resonance in engineering and design to ensure the stability and performance of systems.