Some substances are biodegradable because they can be broken down by microorganisms like bacteria and fungi into simpler, harmless components through natural biological processes. These substances are typically organic or natural materials, such as cotton, wood, paper, and food waste, which contain chemical structures that microbes can digest. On the other hand, non- biodegradable substances do not break down easily because their chemical structures are resistant to microbial action. These are often synthetic or man-made materials such as plastics, metals, and certain chemicals that lack the enzymes necessary for decomposition by microorganisms. Environmental conditions and the presence of specific microbes also influence whether a substance can biodegrade. Non-biodegradable materials persist in the environment for a long time, leading to pollution issues, while biodegradable materials decompose and return to the ecosystem more benignly.