Dear puja,
In mathematics, a spherical coordinate system is a coordinate system for three-dimensional spacewhere the position of a point is specified by three numbers: theradial distance of that point from a fixed origin, itspolar anglemeasured from a fixed zenithdirection, and the azimuth angle of its orthogonal projection on a reference plane that passes through the origin and is orthogonal to the zenith, measured from a fixed reference direction on that plane. It can be seen as the three-dimensional version of the polar coordinate system.
Thankyou