Permittivity and permeability are two different measures used in electromagnetism. Permittivity measures the ability of a material to store energy within the material. Permeability is a measure of the ability of a material to support the formation of a magnetic field within the material.

 Permittivity is represented by the Greek alphabet ϵ. It tells the number of charges required to generate one unit of electric flux in the given medium. 

SI unit - Farad/meter