what do you mean by activity of catalyst

Catalyst is a substance which increases the rate of reaction without consumed in the reaction.Catalytic activity is not a kind of reaction rate, but it is a property of the catalyst under certain conditions, in relation to a specific chemical reaction.Catalytic activity is usually denoted by the symbol z and measured in mol/s, a unit which was called katal which is the SI unit for catalytic activity.. Catalytic activity of one katal (Symbol 1 kat = 1mol/s) of a catalyst means an amount of that catalyst that leads to a net reaction of one Mol per second of the reactants to the resulting reagents.A catalyst may and usually will have different catalytic activity for several distinct reactions.