the Nyquist theorem

The Nyquist theorem states that to accurately capture or reconstruct a signal without losing information, you need to sample it at least twice the highest frequency present in the signal. In other words, if a signal contains fast-changing components, you must take samples at a rate twice as fast as those components to recreate the original accurately. This principle ensures digital representations of analog signals are faithful, preventing errors known as aliasing, which can distort the reconstructed signal.