The term recycling refers to the processing of used manufactured products in such a way that the materials are turned into new products, ready to be re-used. Most materials can be recycled, although harder substances may cost more to process, making their re-use inefficient. Paper, plastic, glass, tin, and many textiles are all relatively easy to process for recycling. Despite the similarity in purpose and process, when organic materials such as foods and plants are re-used the process is known as composting rather than recycling.
Recycling is done for a number of reasons, the most obvious of which is to reduce the amount of natural resources which are consumed for new products. It is also done to save energy, prevent water and air pollution, and to prevent the build up of garbage and the proliferation of landfills.
If recycling were a perfectly efficient process you would be able to take old wasted products, and convert them into the same amount of the same product, only unused. However, there is an energy expenditure that is used when processing recycled materials, which can drive up the cost of manufacturing certain goods. That is why high end materials such as paper and pencils are often turned into lower grade recycled materials such as cardboard.
Salvage is another form of recycling, in which valuable substances or components of a used product are reclaimed without actually reusing the rest of the product. This is done with the lead found in batteries, as well as the gold parts that are found in computer chips.
While recycling is considered to be a method for reducing waste and preserving the health of the natural world, opponents claim that it is actually a wasteful process that uses up more resources than it produces. These criticisms are often specifically targeted at state mandated recycling initiative. However, even if the cost of production is higher it may be justified due to the cost of maintaining the product in a landfill after it is used.