The introduction of distortions or artefacts into digital information during processing operations. In graphics, aliasing can cause edges to appear jagged. In audio, aliasing results in artefacts below the Nyquist frequency, sometimes called aliasing distortion. To avoid aliasing, audio signals must be low-pass filtered to remove energy at or above the Nyquist frequency before sampling. Anti-aliasing operations can be performed to prevent or mitigate the results of aliasing. See anti-aliasing.