what do you mean by catalyst
Catalyst: A Catalyst is that substance, which either initiates a chemical reaction or accelerate the reaction without undergoing any permanent change in itself.
However, they affect the rate of reaction by increasing the speed of reaction.
The catalysts are called as the chemical activators which do not get involved in the product formation ,but their presence causes a reaction to occur faster.
Ex: some metals like; Ni (nickel), Pt (Platinum), Fe (Iron) etc,. or chemical compounds like alcohols, KMnO4 etc.