MARPAT definition

MARPAT (short for MARine PATtern) is a digital camouflage pattern in use with the United States Marine Corps, introduced with the Marine Corps Combat Utility Uniform (MCCUU), which replaced the Camouflage Utility Uniform. The pattern is formed by a number of small rectangular pixels of color. In theory, it is a far more effective camouflage than standard uniform patterns because it mimics the dappled textures and rough boundaries found in natural settings. This is caused by how the human eye interacts with pixelated images. It is also known as the "digital pattern" or "digi-cammies" because of its micropattern (pixels) rather than the old macropattern (big blobs).

The United States Marine Corps has patented MARPAT, including specifics of its manufacture.[1] By regulation, the pattern and items incorporating it, such as the MCCUU and ILBE backpack, are to be supplied by authorized manufacturers only and are not for general commercial sale, although imitations are available such as "Digital Woodland Camo" or "Digital Desert Camo".

There were initially three MARPAT patterns: Woodland, Desert, and Urban. Currently, only the Woodland and Desert patterns are used by the Marine Corps, replacing the U.S. Woodland pattern and the U.S. Three Color Desert pattern. Webbing and equipment worn with MARPAT Woodland and MARPAT Desert is produced in Coyote Brown, a mid-tone colour common to both the woodland and desert patterns. The Urban pattern was not approved for use. Although a digital snow pattern has also been adopted on cold weather training over-garments, this uses a different pattern from the Canadian company Hyperstealth [7]

Courtesy of wikipedia

I just see this missunderstood quite often thought it could clear up some questions maybe

Also to add to this if you're going for a true Marine load out deserts are the only cammies the sleeves are rolled on. Woodlands the sleeves stay down.