The electrical conductivity of a material is an intrinsic, bulk property that, together with the spatial dimensions and shape of a sample of the material, determines the electrical conductance (and therefore electrical resistance) of that sample.
Electrical conductivity is usually represented by the symbol σ.
Electrical conductivity is defined by the equation
σ = L / R A
where R is the electrical resistance of a sample of material of length L and uniform cross-sectional area A.