Destructive interference occurs when two waves meet and combine in such a way that they cancel each other out. This phenomenon happens when the crest of one wave aligns with the trough of another, resulting in a reduction or complete elimination of the wave's amplitude. It is commonly observed in various contexts, such as sound waves and light waves. In practical applications, destructive interference can be utilized in noise-canceling headphones, where sound waves from the headphones are designed to counteract ambient noise. This technology effectively reduces unwanted sounds, providing a clearer listening experience for users.