Plastics derived from the biological world and/or intended to return to it have grown significantly in recent years. A very large number of these new plastics (bio-sourced, biodegradable) are currently available on the market and a growing number of applications are associated with them. It therefore seems important to take an overview of the definitions of these materials and to take a few examples to illustrate the notions of origin of these plastics and their desired function, particularly in agriculture.