The polar coordinate system is a two-dimensional coordinate system that uses a distance and an angle to define a point's position. Instead of using the traditional Cartesian coordinates, which rely on horizontal and vertical distances, polar coordinates specify a point by its distance from a reference point (the origin) and the angle from a reference direction (usually the positive x-axis). In polar coordinates, a point is represented as (r, θ), where r is the radial distance and θ is the angle measured in degrees or radians. This system is particularly useful in fields like mathematics, physics, and engineering, where circular and rotational motion are common.