Parseval's theorem

Parseval's theorem states that the total energy of a signal, whether analyzed in its original time form or in its frequency components, remains the same. In practical terms, if you take a sound wave and break it down into its individual frequencies, the sum of the energy across those frequencies equals the total energy of the wave itself. This principle is important in various fields like signal processing and communications, as it assures us that no information is lost when transforming between time and frequency representations.