Have you ever tried to run the wrong way down an escalator? then you have experienced a dynamic equilibrium.You are moving up, it is moving down and yet, your actual position isn't changing. In a reaction this means that: the forward reaction is happening e.g. A + B --> CAND the backward reaction is happening too e.g. C -->A + BSo as some molecules of A+B are joining to form C, also some C molecules are splitting apart to become A + B.