Imaginary number

An imaginary number is the mathematical representation of the square root of negative numbers $$j = \sqrt{-1}$$.

Imaginary numbers are represented (at least in rectangular form) in the form of multiples of $$j$$, (Example $$1j, 16j, \sqrt{2}j$$), where the $$j$$ doesn't stand for anything than to indicate the number next to it is imaginary.