The separation of positive and negative charges in a compound is known as polar character. The dipole moment has magnitude as well as direction so it is a vector quantity.
The significance/application of dipole moment are:
It is useful in finding the polar nature of the chemical bond.
It is useful in finding the shape of molecules. Molecules that have zero dipole moment are symmetrical
Is helps in seeing the difference in cis- and trans- isomers. Isomers having high dipole moments are trans-isomers. Isomers having low dipole moment are cis-isomers.
It helps in finding the percent ionic character.
Answer
The separation of positive and negative charges in a compound is known as polar character. It has significance in finding the polar character and ionic character of the molecule.