A drill bit is a tool used to cut or crush rock. With rotary drilling, a hole is drilled by the continuous turning of a drill bit. The drill bit is the mechanism that cuts into the ground layers to reach the gas deposit or to cut a core sample.
A drill bit is a cutting tool used in a drill to remove material to create holes, almost always of circular cross-section. Drill bits come in many sizes and shapes and can create different kinds of holes in many different materials.
Drilling is a cutting process in which a drill bit is used to cut or enlarge a hole in a solid material. Drilling is the process of cutting holes in a solid material using a rotating cutting tool.
Characteristics of Drill Bits. There are several standard aspects of drill bit geometry: the spiral, the point angle, the lip angle, and the functional length. the spiral (sometimes called the rate of twist) is the steepness of the groove that spirals along the edge of the bit.
Drill bits are primarily used for creating circular holes in materials from drywall and wood to metal and masonry. They might create a hole for an anchor or fastener, or a passage to feed wiring. Bits are sold individually and in multi-sized sets, commonly called drill indexes.
 

Loosen the chuck (the black circular section on the front of the drill) by twisting it counterclockwise to widen the diameter of the jaws that clamp onto the drill bit. Insert the shank (smooth part) of the drill bit into the jaws, and re-tighten the chuck until the drill bit is secured.
Drill bits make holes in a variety of different common materials. These include different types of wood, metal, plastic, ceramic tile, porcelain and concrete. Different types of drill bits made for steel, aluminum, copper, cast iron, sheet metal, fiberglass, brick, vinyl flooring and more are also available.