They aren't related. They appear in SUSY Lagrangian as L=∫d4θK(Φ,¯Φ)+(∫d2θW(Φ)+c.c.),
here K is a real-valued function of a chiral field Φ and its conjugate ¯Φ, named Kahler potential, while W is an analytic function of Φ, named superpotential.
Being rewritten in the component fields, K contains kinetic terms of these fields and certain interactions required by supersymmetry, while W contains potential (and mass) terms plus, again, interactions dictated by supersymmetry.