A Biodegradable product has the ability to break down, safely and relatively quickly, by biological means, into the raw materials of nature. Once biodegraded, this product would safely become part of the natural ecology of its environment. Another definition : Biodegradability means that a material has the proven capability to decompose into nontoxic soil, water, carbon dioxide or methane (source : biosmartpackaging.com).
Biodegradable bags are bags made from materials that are able to decompose under specified conditions of light, moisture and oxygen. Often composting conditions or exposure to sun, moisture and oxygen are needed : degradation is slow in landfills. Many stores and companies are beginning to use different types of biodegradable bags to comply with perceived environmental benefits (source : wikipedia).
BeFre bags made of jute, coton, juco or bambou are biodegradable as they are completely natural and are able to break down in raw materials of nature.