Segregation of waste is important for properly disposing of the vast amount of garbage modern society produces in an environmentally conscious manner. Different components of waste have very different properties, and grouping them by type allows for proper processing or storage. The main categories are biodegradable and non-biodegradable wastes, but there are subcategories in each that are often separated as well.

Biodegradable wastes are quickly broken down by microorganisms in normal environmental conditions. This category is mainly food scraps. It is further split into animal-derived and plant-derived waste. Animal waste must be handled separately from plant waste, especially if the food waste is intended for animal feed. In addition, the organisms that help break down biodegradable waste are different for animals and plants, with animal-derived waste posing a greater health risk.

Non-biodegradable waste is the source of much of humanity’s waste disposal problem. Paper, metals, glass, plastic and textiles are all classified as non-biodegradable, due to the long or indefinite time it takes for them to break down naturally. Many of these wastes, but not all, can be recycled.