Glitch Art is the act of causing a fault or taking advantage of a preexisting fault in hardware or software to cause it to act in an unexpected, possibly artistic, way.
Glitches in hardware can be cause through a method called Circuit Bending. This is where the actual wiring and circuitry of a device is altered, usually by soldering wire jumpers to various points on the circuit board. This process can be destructive. On low power devices, battery only devices, like small electronic pianos, it is usually safe. But on high power devices that plugin to wall outlets, like video game consoles and desktop computers, serious injury can occur.
Here are a few resources on Circuit Bending:
Glitches can be cause in a number of ways in software. One way is through a method called Datamoshing, the corrupting of already saved data or causing the data to be saved in a manner that takes advantage of defects or limitations of a format.
One way we can to Datamosh is by removing key frames, also known as I-Frames.
In many lossy video formats, including MP4, each frame does not actually include an entire image of the frame. Instead most frames, known as P-Frames, only contain pieces of the image that move. Complete images of the frame, called key frames or I-Frames, are only created at points of significant change in the image.
When you remove the I-Frames, it causes decoding errors at points of significant motion that causes the image to "hang."