Which device is used to shred food waste into small pieces?

A garbage disposal unit is a device, usually electrically powered, installed under a kitchen sink between the sink's drain and the trap. The device shreds food waste into pieces small enough—generally less than 0.079 in in diameter—to pass through plumbing. In the United States, 50% of homes had disposal units as of 2009, compared with only 6% in the United Kingdom and 3% in Canada.

Source: Wikipedia