Clipping is the hard distortion that occurs when a signal tries to exceed the maximum level the system can represent — 0 dBFS in the digital domain — and its peaks are simply flattened to the ceiling. The squared-off waveform is rich in harsh high harmonics, the crackle you hear on an overdriven recording. Digital clipping is unforgiving and, once printed into a file, permanent: the lost peak information cannot be recovered. It happens at capture if input gain is too high, and in processing if gains sum past full scale. Defences are adequate headroom, a true-peak limiter before the ceiling, and metering that catches consecutive max-value samples.
