The word itself comes from French slang "camoufler," to disguise, and military use exploded through the two World Wars — France's WWI camouflage units are the well-known starting point. The US "Woodland" (M81) pattern settled into its now-familiar form between 1948 and 1981, and pixel-block "digital camo" (like MARPAT) arrived in the 2000s, based on research suggesting fractal, pixel-scale patterns disrupt the human eye's edge detection better than smooth blobs do at a distance.
In fashion it broke free of military gear in the 1990s, when hip-hop and streetwear culture adopted it and turned it into a mainstream pattern in its own right.
Structurally the defining rule is that nothing aligns — irregular organic blotches in three to five earth tones, sized differently, overlapping with no underlying grid. In CSS, several radial-gradient blotches at different positions and sizes stack together, then filter: blur() softens every edge so it reads as a naturally bled stain rather than a printed outline.
When to use
Use for outdoor/tactical branding and streetwear texture. Avoid pairing it with real military insignia or rank marks.