An auger is a drill

Drill

A drill or drill motor is a tool fitted with a cutting tool attachment or driving tool attachment, usually a drill bit or driver bit, used for drilling holes in various materials or fastening various materials together with the use of fasteners. The attachment is gripped by a chuck at one end of...

ing device, or drill bit

Drill bit

Drill bits are cutting tools used to create cylindrical holes. Bits are held in a tool called a drill, which rotates them and provides torque and axial force to create the hole. Specialized bits are also available for non-cylindrical-shaped holes....

, that usually includes a rotating helical screw blade

Screw (simple machine)

A screw is a mechanism that converts rotational motion to linear motion, and a torque to a linear force. It is one of the six classical simple machines. The most common form consists of a cylindrical shaft with helical grooves or ridges called threads around the outside...

 called a "flighting" to act as a screw conveyor

Screw conveyor

A screw conveyor or auger conveyor is a mechanism that uses a rotating helical screw blade, called a "flighting", usually within a tube, to move liquid or granular materials. They are used in many bulk handling industries...

 to remove the drilled out material. The rotation of the blade causes the material to move out of the hole being drilled.

An auger used for digging post holes is called an earth auger, soil auger, or mechanized post hole digger

Post hole digger

A post hole digger is a tool used to dig narrow holes to install posts, such as for fences and signs.There are different kinds of post hole diggers. The pictured type is jabbed into the ground in the open position until the blades are buried. At that point the handles are pulled apart to close the...

. This kind of auger can be a manually turned, handheld device, or powered by an electric motor or internal-combustion engine, possibly attached to a tractor (being provided with power by the tractor engine's power take-off

Power take-off

A power take-off or power takeoff is a splined driveshaft, usually on a tractor or truck, that can be used to provide power to an attachment or separate machine. It is designed to be easily connected and disconnected...

 as shown). Handheld augers can also be used for making holes for garden planting.
Wood augers have a screw to pull them into the wood, as a gimlet has, and a cutting lip that slices out the bottom of the hole. The auger bit, meant to be used in a brace, also has cutting spurs to cut a clean circle deeper than where the lips scrape out the wood.

In construction, augers are used for special drilling rig

Drilling rig

A drilling rig is a machine which creates holes or shafts in the ground. Drilling rigs can be massive structures housing equipment used to drill water wells, oil wells, or natural gas extraction wells, or they can be small enough to be moved manually by one person...

s to dig holes for deep foundation

Deep foundation

A deep foundation is a type of foundation distinguished from shallow foundations by the depth they are embedded into the ground. There are many reasons a geotechnical engineer would recommend a deep foundation over a shallow foundation, but some of the common reasons are very large design loads, a...

 piles. Another use is for piles forming a piling retaining wall

Retaining wall

Retaining walls are built in order to hold back earth which would otherwise move downwards. Their purpose is to stabilize slopes and provide useful areas at different elevations, e.g...

, which can be constructed in the same way as foundation piles.

Augers are also used by ice fishermen

Ice fishing

Ice fishing is the practice of catching fish with lines and fish hooks or spears through an opening in the ice on a frozen body of water. Ice anglers may sit on the stool in the open on a frozen lake, or in a heated cabin on the ice, some with bunks and amenities.-Locations:It is a popular pastime...

to drill holes to fish through. These can be either gas- or hand-powered.