What are vectors and matrices?

What are vectors

In the simplest form, a vector is just a list of number v = [1, 2, 3]. Mathematically speaking, the correct definition is that a vector is an element in vector space. Concretely, a vector is said to have a magnitude and a direction. For a vector v = [a, b], the magnitude is:

$$|v| = \sqrt{a^2 + b^2}$$

For the direction