An electric dipole consists of two equal and opposite charges and separated by a small distance .
The Electric Dipole Moment is defined as a vector of magnitude with a direction from the negative charge to the positive charge. In many molecules, though the net charge is zero, the nature of chemical bonds is such that the positive and negative charges do not cancel at every point. There is a small separation between the positive charge centres and negative charge centres. Such molecules are said to be polar molecules as they have a non-zero dipole moment. The figure below shows an asymmetric molecule like water which has a dipole moment C-m.