Reduce - to use less. Incorporates common sense ideas like turning off the lights, using rain barrels, and taking shorter showers, but also plays a part in composting, and low-flow or compostable toilets.
Reuse - elements of the discarded item are used again. Initiatives include waste exchange and composting (nutrients). Includes the terms repair, regift, and upcycle. Safe collection, storage, treatment and disposal (re-use or recycling) of human excreta. Management (re-use or recycling) of solid waste (rubbish). Drainage and disposal (re-use or recycling) of household waste water... also referred to as grey water.
Recycle - discards are separated into materials that may be incorporated into new products. This is different from reuse in that energy is used to change the physical properties of the material. Initiatives include composting, construction materials recycling. Within recycling there is distinction between two types: