u can explore this applet
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1918.0
i just added 29Sept2010
6 added KE = 0.5*m*v^2 ;  PE = q*Vnet;  TE = KE+PE; due to question by leeyiren http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1965.new#new

in the context of a charge in a potential V
Charge = q
Potential Energy = q*V where V could be = (1/4*pi*elipson)Q/r
Kinetic energy = + 0.5*m*v^2
Electric charge is a physical property of matter which causes it to experience a force when near other electrically charged matter. http://www.answers.com/topic/electric-charge
energy is a quantity that is often understood as the ability to perform work. http://en.wikipedia.org/wiki/Energy

the analogue of your question is what is the difference between mass and energy
The inertial mass of an object determines its acceleration in the presence of an applied force http://en.wikipedia.org/wiki/Mass
energy is a quantity that is often understood as the ability to perform work. http://en.wikipedia.org/wiki/Energy

does it help to see the parallelism of the concept to mass?