To camouflage something is to make it obscure, to hide it and to make it meld into the background. Camouflage is often used by military forces in order to be harder to spot and defeat. A trademark of modern armed forces are the camouflage clothing worn, a practice dating from after the Korea war.
Camouflage is always adapted to the environment in which it is employed, and will look very different in a dense forest than on a snow covered tundra. Likewise is the camouflage clothing worn by soldiers adapted to the environment where they are expected to engage in combat.
The patterns often seen on camouflage clothing, masking cloth and vehicle paints are carefully constructed to decieve the human eye by breaking up the boundries that define sharp edges and human silhuets.
Successful camouflage is often an essential part of modern military tactics.