what is Le chatelier principle?? examples

Le Chatelier's principle states that when a system at equilibrium is disturbed, it will shift to partially counteract the change. This principle can be used to predict how changes in concentration, temperature, or pressure will affect chemical reactions. 

Le Chatelier's principle is also known as the equilibrium law, Braun–Le Chatelier principle, or Le Chatelier–Braun principle.

Examples

If the concentration of a reactant is increased, the equilibrium shifts to reduce the concentration of that reactant. 
If a product is removed, the equilibrium shifts to replace the removed product.