What is radial distance?

Radial distance refers to the straight-line distance from a central point to a point in space, often used in polar or spherical coordinate systems. In a two-dimensional context, it is the distance from the origin (0,0) to a point (r, θ), while in three dimensions, it describes the distance from the origin to a point defined by its spherical coordinates (r, θ, φ). This concept is crucial in fields such as physics, engineering, and astronomy, where understanding the spatial relationship from a central point is essential.