Definition of Catalyst
Catalyst is a substance that is responsible to speed up the reaction. They only enhance the rate but are not consumed up in the reaction. They also help in lowering the activation energy required for the reaction. Activation energy is defined as the minimum amount of energy that is required to initiate the chemical reaction.
A large number of industrial processes use catalysts for increasing the rate of the chemical reactions so that the industrial products can be manufactured in less time. In biological terms, the enzymes are known to be the biological catalysts as they speed up the reactions but remain unused throughout the reaction process.