biodegradable vs compostable

A material can be claimed to be biodegradable if it is transformed into CO2, water and biomass by micro-organisms within a defined period of time under certain temperature and environmental conditions (compost/soil/water). 

A finished product is considered compostable if, when made of biodegradable materials, it disintegrates within a specified time in that environment without ecotoxic effects on it. 

It is understood that the ability of a product to disintegrate within the prescribed time depends on its shape (thickness) and the temperature of the compost (cold/domestic or hot/industrial)..