There are a lot of different Ice Machine Options... let's try and simplify.

There are a few common types of Ice:

Flaked Ice
Nugget / Cubelete/"Sonic" Ice
Full Cube
Half Cube
Crescent Cube

Range of Ice machine sizes (production amounts) of ~300lbs - 2000lbs per day. (22", 30" & 48" Wide)

Across all of those sizes you have different cooling types of equipment:

Air - suitable for most use cases
Water - ideal for high heat enviroments where the customer is not responsible for their water bill
Remote - required for high heat enviroments

Depending on the size & cooling type, your power & water needs are different:

Water = From 3/8" up to TWO 1/2" water lines.
Power = From your standard 110V machine to Three Phase 240V machines.

& Finally, on top of all of this, you then have different Bin Sizes. (How much Ice does the machine hold). 300LBS - 1600+ LBS. (Ranging from 22" wide to 60" Wide).