Hardware malfunction: In computer graphics, visual artifacts may be generated whenever a hardware component such as the processor, memory chip, cabling malfunctions, etc. causing data corruption. Malfunction may be caused by physical damage, overheating, insufficient voltage, and sometimes due to GPUoverclocking, etc. Common types of hardware artifacts are texture corruption and T-vertices in 3D graphics, and pixelization in MPEG compressed video.
Software malfunction: Similarly to hardware malfunction, artifacts may be caused by software issues such as bugs in the algorithms, such as decoding/encoding introducing artifacts into audio or video, or a poor pseudo-random number generator would introduce artifacts distinguishable from the desired noise into statistical models.
Aliasing: Digital imprecision generated in the process of converting analog information into digital space due to the limited granularity of digital numbering space. In computer graphics, aliasing is seen as pixelation.
Rolling shutter, the line scanning of an object which is moving too fast for the CMOS camera to capture a unitary image.