Definition - What does Catalyst mean?
A catalyst is a substance or a reagent which increases the rate of a chemical reaction by lowering the activation energy and adopting an alternate route for the reaction. A catalyst does not undergo any permanent chemical change, so it can be recovered when the reaction is completed. Transition elements often act as catalysts and small amounts are sufficient to increase a reaction's rate.
Corrosionpedia explains Catalyst
When manufacturing something at a large scale in an industry, it is very important to use the optimum conditions to achieve cost-effectiveness and sufficient yield in minimum time. A catalyst helps achieve those conditions. For instance, iron is used as a catalyst in the Haber process, and vanadium oxide is the best catalyst for the contact process.
Some reactions are called autocatalytic, as one of their products acts as a catalyst for the reaction. It is important to note that a catalyst does not affect the equilibrium. Instead, it helps to achieve equilibrium in the minimum time, making it possible to achieve sufficient yield.