A drill is a tool with a rotating drill bit used for drilling holes in various materials. Drills are commonly used in woodworking and metalworking.The drill bit is gripped by a chuck at one end of the drill, and is pressed against the target material and rotated. The tip of the drill bit does the work of cutting into the target material, slicing off thin shavings (twist drills or auger bits) or grinding off small particles (oil drilling).

The earliest drills were probably bow drills. The invention of the electrical drill is credited to Mr. Arthur James Arnot[1], in 1889, at Melbourne, Australia. Wilhelm Fein[2] invented the portable electric drill in 1895, at Stuttgart, Germany. In 1917, Black & Decker patented a trigger-like switch mounted on a pistol-grip handle.[3]

There are many types of drills; some powered manually and others using electricity or compressed air as the motive power. Drills with a percussive action (such as hammer drills, jackhammers or pneumatic drills) are usually used in hard materials such as masonry or rock. As well, drilling rigs are used to bore holes in the earth to obtain water or oil. An oil well, water well, or holes for geothermal heating are created with large drill rigs up to a hundred feet high. Some types of hand-held drills are also used to drive screws.

The hammer drill is similar to a standard electric drill, with the exception that it is provided with a hammer action for drilling masonry. The hammer action may be engaged or disengaged as req

The rotary hammer drill (also known as roto hammer drill or masonry drill) is an electric drill type dedicated to drilling holes in masonry. The rotary hammer drill is a percussion drill that uses a weight to create the impact force on the masonry bit. Generally, the drill chuck of the rotary hammer drill is designed to hold SDS drill bits. Some styles of this drill are intended for masonry drilling only and the hammer action cannot be disengaged. Other styles allow the drill to be used without the hammer action for normal drilling.

A cordless drill is a type of electric drill which uses rechargeable batteries. These drills are available with similar features to an AC mains-powered drill. They are available in the hammer drill configuration and most also have a clutch setting which allows them to be used for driving screws.

For continuous use, a worker will have one or more spare battery packs charging while drilling, so that he or she can quickly swap them, instead of having to wait several hours during recharges.

Early cordless drills started with interchangeable 7.2V battery packs, and over the years the battery voltage has been increased to 18V, and higher, allowing these tools to produce as much torque as many mains-powered drills. The drawback of most current models is the use of nickel-cadmium (NiCd) batteries, which develop a "memory effect" or internal short circuits due to dendrite growth, severely limiting their useful life, and posing a hazardous materials disposal problem. Drill manufacturers are now introducing lithium ion batteries, most notably Makita Electric Works and

Milwaukee Electric Tool Corporation. The main advantages are lack of memory effect and very short charging time. Instead of charging a tool for an hour to get 20 minutes of use, 20 minutes of charge can run the tool for an hour. Lithium-ion batteries also have a constant discharge rate. The power output remains constant until the battery is depleted, something that nickel-cadmium batteries also lack, and which makes the tool much more versatile. Lithium-ion batteries also hold a charge for a significantly longer time than nickel-cadmium batteries, about 2 years if not used, vs. around 4 months for a nickel-cadmium battery.