The difference between the xy plane and the complex plane is that in the first one we are representing an ordered pair (that is, two numbers) while in the complex plane we are representing only one number (but this number can be decomposed in an real part and an imaginary part).
Now, they are similar in that the construction is the same, that is, they are both made of two perpendicular lines that we call axis, the intersection is called the origin and is represented by the zero in each set.
