Waste (also known as rubbish, trash, refuse, garbage, junk, and litter) is unwanted or useless materials.
Waste is directly linked to human development, both technological and social. The compositions of different wastes have varied over time and location, with industrial development and innovation being directly linked to waste materials. Examples of this include plastics and nuclear technology. Some waste components have economic value and can be recycled once correctly recovered. Waste is sometimes a subjective concept, because items that some people discard may have value to others. It is widely recognized that waste materials can be a valuable resource, whilst there is debate as to how this value is best realized. Such concepts are colloquially expressed in western culture by such idioms as “One man’s trash is another man’s treasure.”
Litter refers to waste disposed of improperly.
There are many waste types defined by modern systems of waste management, notably including:
Municipal Waste includes Household waste, Commercial waste, and Demolition waste
Hazardous Waste includes Industrial waste
Bio-medical Waste includes Clinical waste
Special Hazardous waste includes Radioactive waste, explosives waste, and Electronic waste (e-waste)
There are many issues that surround reporting waste. It is most commonly measured by size or weight, and there is a stark difference between the two. For example, organic waste is much heavier when it is wet, and plastic or glass bottles can have different weights but be the same size. On a global scale it is difficult to report waste because countries have different definitions of waste and what falls into waste categories, as well as different ways of reporting.