Types of Ice
Ice can be divided into colors and shapes. Clear ice is restaurant-quality, gourmet ice whose impurities have been removed so the cubes do not have the "cloudy" appearance of regular ice. This ice is completely odorless and tasteless, however, clear icemakers are always more expensive. Ice can also be made in a variety of shapes, including actual cubes, cylinders, and crescents. Cylindrical ice is rounded and often has an indentation in the top and a rounded out bottom. Crescent ice cubes are similar to what many icemakers in refrigerators make, long with flat tops and round bottoms. There are not currently family-sized ice machines on the market that make crushed or flaked ice, only commercial-sized machines.

Portable Icemakers
Portable icemakers do not need a permanent water line; they plug into a standard outlet and you only need to pour water into them. These will make ice very quickly, however, they are not freezers and thus will not keep the ice frozen. The ice will melt, and the machine will recycle the water to make more ice. They will also only hold a small fraction of their full icemaking capacity, so you will need to empty them frequently if you need more ice to be made.

Built-In Icemakers
Built-In icemakers should be installed by a professional plumber. They take a permanent water line, and some of them also need a drain line. These can store much more ice than a portable, and can keep it frozen longer.

Some built-in icemakers can be used outdoors, but only those that specifically say so. Otherwise they will not be able to keep the ice frozen in high ambient temperatures. Some built-in icemakers meet ADA standards so they can be easily used by the differently-abled. And, some built-in icemakers can even accept custom door panels so that they will blend in with surrounding cabinetry; their descriptions will specify this if that is the case.

Storage of Ice
Keep in mind that most icemakers have a much greater production capacity than storage capacity. They are capable of making a great deal of ice in a day, but they can only store a small fraction of it. When deciding on an icemaker be sure you know what the production and storage specifications are.