What is polarity  

Polarity is separation of electric charge leading to a molecule having electric dipoles.polar molecule interact through intermolecular forces.for example H2O is a polar molecule but CO2 is non polar molecule in which dipoles cancel each other.

Polarity is a physical property of compounds which relate to other physical properties, such as melting and boiling points or solubility. Bond polarities arise from bonds between atoms of different electronegativity. A molecule can be ionic, polar or non-polar.

A polar molecule is formed when one end of a molecule has a positive charge and the opposite end has a negative charge, thus creating electrical poles. A non-polar molecule does not have charges at the ends as the electrons are distributed more symmetrically and cancel each other out.

When trying to create a solution, a polar molecule does not mix with a non-polar molecule. An example of this is seen with water, a polar molecule and oil, anon-polar molecule; the two molecules cannot mix to form a solution. However, water and alcohol can mix to form a solution as they are both polar molecules.