A peeler (potato peeler and/or apple peeler) is a metal blade attached to a wooden, metal or plastic handle that is used for peeling certain vegetables, frequently potatoes, and fruits such as apples, pears, et cetera.
There are three main varieties, the Yorkshire (or sometimes called a Lancashire peeler) design involving the blade as an extension of a handle, in much the same way as the blade is attached to a knife. Its use involves grasping the potato in one's left hand and holding the peeler in the fingers of the right hand and the top of the potato with the thumb of the right hand. The action then involves using the fingers of the right hand to pull the peeler's blade over the skin of the potato, turning it slightly so that it digs in and removes the potato skin, in a movement towards the right thumb. This also uses the grip of the right thumb to allow the movement of the fingers of the right hand to be based on the contraction of the right hand in a claw movement which is easier to accomplish than if the movement of the right fingers were to be controlled by the right arm or wrist.
Note: left-handed people usually transpose the hands in the above explanation.
The second variety more closely resembles a safety razor (sometimes it is called a Y-peeler (due to its shape), Rex peeler, yoke peeler, or speed peeler), with the blade perpendicular to the handle, is used with a similar action to a razor, shaving off skin in strips parallel to the handle. Most speed peelers have an 'eye gouger' beside the blade, a loop of metal used to dig out eyes and blemishes from the potato.
The third variety has no official name, but is used extensively in Australia, where the design originated. It was designed in about 1947 by a company called Dalsonware in Melbourne who call it the "Dalson Classic Aussie Peeler". It consists of a plastic handle which extends upwards to support both the base and tip of a partially rotating blade. This type of peeler is also typical of a general fruit and vegetable peeler in Canada.
For safety reasons, when being used to peel an item held in the hands, the blade should be kept still, and the item pushed against it. If a potato is grasped in the left hand and the peeler in the right, the thumb of the right hand is used to push the potato backwards against the blade. When used on a chopping board (when peeling carrots, for instance), it should be drawn parallel to the body, away from the limb supporting the item. Holding the peeler in the right hand, the carrot is supported against the board with the left hand, and the peeler is drawn from left to right. A speed peeler must never be held such that the handle is facing away from the user, because peeling with such a posture is awkward, and may cause the peeler to slip. A speed peeler must also never be 'pushed', but always drawn such that the blade follows the handle, otherwise the peeler may slip if the blade catches. In all cases, the fingers holding the peeler should be kept as far back from the blade as possible.