The Nyquist rate is the minimum sampling rate required to accurately capture a continuous signal without losing information. According to the Nyquist-Shannon sampling theorem, this rate is twice the highest frequency present in the signal. For example, if a signal contains frequencies up to 1,000 Hz, the Nyquist rate would be 2,000 samples per second. Sampling below the Nyquist rate can lead to aliasing, where higher frequency components are misrepresented as lower frequencies, distorting the original signal. Therefore, adhering to the Nyquist rate is crucial in fields like digital audio and signal processing to ensure fidelity in the representation of signals.