electrostatics - What is electric dipole?

I don't understand the electric dipole as it is described in my physics book. According to what I have read in my chemistry book, I know that the dipole is the gain of partially negative charge in the electronegative end and vice versa. This results in a type of weak Van der Waal force. However, in physics I don't find the same explanation. In physics, it is described as the product of the magnitude of charge, $q$, and distance between the two equal and opposite charges, $\textbf{d}$. How can both of these definitions be the same?