It's a manual food processor for your fruits and veggies, except with greater precision. It's like running your food through a knife instead of running a knife through your food. As far as we know, it was the French who invented it, however it's puzzling how it got its name from a musical instrument. In French it's Mandoline, and in English it's Mandolin; either is acceptable.
Professionals choose adjustable platform mandolines, generally being the most durable. Though initially not as easy to operate as the fixed platform type, you'll find them to be a joy once you get used to yours.
Fixed platform mandolines are very easy to use, and preferred by many cooks for their simplicity of design, especially when a limited number of thickness settings are acceptable. Insert the correct size thickness plate and start slicing.
A turning slicer's continuous strands of fruit and vegetables have long been used in Asian cooking. Thin strands make for faster cooking time and more tender, flavorful results in soups and stir fry. The beautiful strands also make wonderful garnishes.
Very thin matchstick slices a few inches long are quickly and easily made with the flat mandolines.
Safety first! The blades are sharp and require special attention. Always use a safety guard with your mandoline, or take special precautions when your fingers get close to the blades, both while in use and when cleaning.
Cleaning mandolin slicers should be done immediately after use, to prevent food from drying on the parts. Blades should be washed by hand. If approved for dishwasher use, carefully position them where they won't cut or damage other utensils with their sharp blades. Steel units should be hand washed, dried immediately, and lightly oiled before storing. (A small artists brush and a well of mineral oil make this task easy and painless.)
Choppers are great for small jobs, when it is more convenient than using a food processor or a mandoline slicer. Some choppers even have blades that rotate automatically as you chop, to help cut your ingredients more evenly.