What role does ceramsite play in flowerpots?

Ceramsite has some gaps, which can play the role of air permeability and water permeability.

In order to keep the soil hydrophobic, you can spread a layer on the bottom of the flowerpot and then add soil to avoid water accumulation.

It also has the function of water and fertilizer conservation, can absorb water and nutrients, and can be mixed with ceramsite to plant flowers. There is also a certain aesthetic, and you can choose some painted pottery.