What is shape-selective catalysis?

(N/A) catalytic reaction that depends upon the pore structure of the catalyst and the size of the reactant and product molecules is called shape-selective catalysis.
For example, catalysis by zeolites is a shape-selective catalysis.
The pore size present in zeolites ranges from $260-740 \, pm$.
Thus, molecules having a size larger than the pore size cannot enter the zeolite cavities and undergo the reaction.