To specify the position of an object, we need a point with respect to which we identify the position of that object. This point is known as the origin or reference point.
Consider a man starts walking from point O. First he goes to point P and then to point Q. as we can see in the given image.
We can say that the position of the object is OP form the origin O in direction of x-axis and PQ from origin O in direction of y-axis. In term of co-ordinate system we say it as (OP, PQ) or (5,4) in term of actual value of axis.