Orthogonal Vectors
Orthogonal vectors are a pair of vectors whose dot product is equal to zero. The relationship between these two vectors is that they intersect at a $90^0$ angle, therefore are perpendicular to each other.
For example, two vectors $a$ and $b$ such that:
$$a = \begin{bmatrix} 1 \\ 2 \\ 0 \end{bmatrix}, b = \begin{bmatrix} 2 \\ -1 \\ 10 \end{bmatrix} $$
are orthogonal vectors because their dot product:
$$\begin{bmatrix} 1 \\ 2 \\ 0 \end{bmatrix} * \begin{bmatrix} 2 \\ -1 \\ 10 \end{bmatrix} = (1*2) + (2*-1) + (0*10) = 2 + (-2) + 0 = 0 $$
import numpy as np
a, b = np.array([1, 2, 0]), np.array([2, -1, 10])
a.dot(b)