Conductivity is the ease with which electrons flows in the electrolyte.It is he conductanc of unit volume of solution kept between two electrode of unit area of cross section and at a distance of unit length.
Molar conductivity is the conductance of volume V of the solution containnig one mole of electrolyte.kept between unit cross section and unit distance.
molar conductivity=k/C
k is cell constant per unit resistance and c is the concentration
Conductivity always decreases with concentration both for strong and weak electrolyte.
For strong electrolyte as the concentration decreases molar conductivity decreases but for for weak electrolyte molar conductivity increases as the dilution increases.