What means "biodegradable" ?

Biodegradable products are nothing more than products that break down during composting and do not release harmful substances. Such products are usually made of naturally occurring polymers, for example, a biodegradable bag can be made from cornstarch or bamboo fibre. Visibly, such a bag will not differ from polyethylene bags (standard, artificial) and the main difference compared to plastic packaging is that the cornstarch bag will decompose when buried in the ground or in a composter just like a regular vegetable, while the polyethylene bag will exist for about 500 years.