Not much but a reversible reaction causes the .
In a reversible reaction, two reactants A + B form to give C + D and also C+D gives A + B. A basic reversible reaction. When it comes to the dynamics, the factor such as temperature, pressure, volume, presence of catalyst, etc. comes into play.
In a , the concentration of the reactants is equal to the concentration of the products. The rate of each reaction is equal thereby causing the net change to be 0. The rate of formation of C+D from A+B is equal to rate of formation of A+B from C+D.