# How does Pooling Layer in CNN introduce invariance to other transformations besides translation

Here is a quote from deeplearningbook which I am trying to process. I am not sure what do they mean by this quote, can someone help me understand please?

Pooling over spatial regions produces invariance to translation, but if we poolover the outputs of separately parametrized convolutions, the features can learnwhich transformations to become invariant to (see ﬁgure 9.9)