When we analyze the kinetics, we can refer to two types of reactions. They are non-reversible and reverse reaction. A Reverse reaction is a chemical reaction which is symbolized by a chemical equation and here the products of a forward reaction become the reactants and the reactants of forward reaction become the products. This type of reverse reaction will be represented by an arrow that is pointing towards the left.

The non - reversible reaction is a one in which the reactants gets consumed completely in the reverse reaction in order to form a product and goes to a completion stage. One good example of this type of reaction would be burning of a paper. Whereas a reversible reaction is one of the interesting processes which includes two types of reactions. One is forward reaction and another one is its mirror image called reverse reaction.

In a reverse reaction, the only reactants that are involved initially are molecules that are around. These molecules get reacted to form the products. These reactants get dwindled and slow down the forward reaction. At the same time the amount of product increases and makes the reactants to disappear. These products start decomposing in order to form the reactants. Thus as the amount of the products gets increasing, the rate of this reverse reaction gets increased.   

Thus, ultimately a time comes where the rate of both forward and the reverse reaction becomes equal. At this point the mixture is said to be at equilibrium. And at equilibrium, the number of product and reactant molecules keeps staying constant. But the identity of the individual molecules of both product and the reactants keeps on changing. Thus a reverse reaction is a chemical reaction where the products can be easily converted back to the reactants under the suitable conditions.  
When A and B reacts to give C and D in a forward reaction, whereas in a reverse reaction, C and D reacts to give A and B. But this process is different from the reversible process that occurs in case of thermodynamics. At the equilibrium point, the concentration of both the reactants and the products can be found thro' the analytical concentration of the reagents and the equilibrium constant denoted by K. The magnitude of this equilibrium constant K actually depend upon the change in Gibbs free energy for a reverse reaction.
Thus, when the change in Gibbs free energy becomes larger, the equilibrium constant also becomes larger and thus at equilibrium reducing the concentration of the reactants to small. This concept of reverse reaction was introduced in 1803 by a person named Berthollet. He introduced it when the formation of sodium carbonate crystals at the edge of a salt lake was observed by him. The equation of which is given by 2NaCl+CaCO3 -> Na2CO3+CaCl2 and the equation for its reverse reaction is given by Na2CO3+CaCl2->2NaCl+CaCO3.