BDU stands for "Battle Dress Uniforms." Camping Survival.com carries a wide variety of BDU, such as basic issue, desert camouflage and City Camo Ultra Force.
The history of the BDU is a long and honorable one. Camouflage uniforms were used in World War II by both the Army and the Marine Corps. While widely used in the Pacific Theater by the USMC, there was not much other use for BDU’s, particularly in the ETO because it was difficult to distinguish the difference between them and the German troops that used the same pattern.
The U.S. found it to be ineffective and that BDU pattern was withdrawn in 1944 — in part because of anticipated friendly fire incidents before D-Day. In 1968, Special Forces units in Vietnam were issued a BDU camouflage pattern rip-stop poplin jungle utility uniform to replace the green sateen used before.
The actual Battle Dress Uniform (BDU) was issued in September 1981 in a woodland pattern. A four-color development of the ERDL pattern, it used two shades of green, one of brown, and black on a cotton-nylon mix. It was issued in two different types, a lighter temperate-weather design, and a heavier cotton winter-weight variant. The temperate BDU is part of the Army's battle dress system (BDS), which includes four camouflage subsystems allowing the Army to operate in temperate, desert, tropical, and arctic environments. There are camouflage patterns to cover all operating environments a soldier might encounter. The U.S. Army Soldier Systems Center at Natick, MA is constantly evaluating improvements to BDU clothing and other gear.
The U.S. military has run trials on many BDU patterns (some of which have been used by other nations) and issued some environment-specific ones. Notably the six-color chocolate-chip camouflage (designed in 1962) and "night-time desert grid," both of which saw use in the 1991 Persian Gulf War. Both were discontinued just after the conflict in 1991.