Origin
The origin is the point where all coordinates are zero.
Explanation
This may be the point 0 on the x-axis, y-axis, and z-axis. It is usually denoted with an O.
Exemple 1
Example 2
In the complex plane, you can also denote any point z = x + iy by its rectangular coordinates (x, iy)
Example 3
In spacetime diagrams, you can denote an event with the coordinates (x, ct).
