So remember, we have reversible and irreversible. Now, Irreversible inhibition basically means that once the inhibitor binds to our enzyme, it will be extremely difficult to actually unbind that enzyme and inhibitor complex. So in this inhibition, once the inhibitor binds to the enzyme, it is very difficult to actually unbind it from that enzyme. And the binding can either be covalent or non covalent. So all three types of these reversible inhibition processes are non covalent, but the Irreversible inhibition can be non covalent as well as covalent. So whenever you hear covalent bonding, that usually means Irreversible inhibition.