👉 In mathematics, an octant is a three-dimensional representation of an object or system. It consists of all points in space that lie on one plane and are at exactly one angle from it (the "fourth" quadrant). Each octant can be divided into four equal parts by the z-axis, which divides it into two halves. For example, consider a cube with vertices at the origin (0,0,0), (1,0,0), (0,1,0),