Four quadrants exist because two axes each divide the plane into:

1. Two independent cuts multiply rather than add. 2. These axes divide a plane into four regions, called quadrants. 3. Each axis on its own splits the plane in two. 4. Two such splits crossing each other give two times two. 5. That is four quadrants. _Source: OpenStax Elementary Algebra 2e (CC BY 4.0), Ch 4 'Graphs', sections 4.1-4.7_