Camo is short for camouflage, which is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Camouflage can be used for a variety of purposes, including military purposes, hunting, and animal survival. The majority of camouflage methods aim for crypsis, often through a general resemblance to the background, high contrast disruptive coloration, eliminating shadow, and countershading. In addition to its use in the natural world, the term "camo" can also refer to clothes made from cloth in a mixture of colors, usually green and brown, like the clothes that military personnel wear. Finally, "CAMO" can also refer to a continuous airworthiness management organization, which is an approval given by a National Aviation Authority (NAA) to a maintenance company within its region that demonstrates the firm meets certain criteria.