The grinders come in both electric and water-powered models. According to StatusClean.com, continuous feed models have an on-off switch on the wall. Batch feed models can only process one batch at a time, and have a lid with a twist handle.
Food waste disposal units drain into either a private septic system or a municipal sewer. In a septic tank, they increase the load of solids that may not separate quickly, according to Inspectapedia.com.
If you have a septic tank, avoid putting in matter that will not break down easily, such as bones and tough or stringy vegetables like asparagus. Inspect it regularly to see if it needs pumping out.
Unless your sink already has wiring for a disposal unit, installation will typically require an electrician to put in a switch and run wires.
The most common problems of disposal units have to do with clogs. Turn off the power before you reach down into the disposal to check for obstructions. You may need to unscrew the pipe under the sink to clear the clog.