Chemical reaction takes place when reactants molecules collide with each other in the reacting atmosphere. Thus, rate of a chemical reaction depends on the collision of reactant molecules and further collision depends upon various factors.
Catalyst is a substance that can change the rate of the reaction, it doesn't consumed in the reaction doesn't change the products of the chemical reaction. A catalyst increases the rate of a chemical reaction.
Increase in temperature, increases the rate of a chemical reaction as temperature is directly proportional to the rate of a chemical reaction.
Concentration of reactants also play a vital role in the rate of a chemical reaction. As the concentration of reactant increases, more will be the collisions, which increases the rate of a chemical reaction.
Thus, three things which increases the reaction rate are Addition of Catalyst, Increase Concentration and Increase Temperature.