Homogenization (from "homogeneous;" Greek, homogenes: homos, same + genos, kind)[2] is the process of converting two immiscible liquids (i.e. liquids that are not soluble, in all proportions, one in another) into an emulsion[3] (an emulsion is a type of colloid, which is a substance microscopically dispersed throughout another substance; when both the dispersed and the continuous substances are liquids, the colloid is called an emulsion). Sometimes two types of homogenization are distinguished: primary homogenization, when the emulsion is created directly from separate liquids; and secondary homogenization, when the emulsion is created by the reduction in size of droplets in an existing emulsion.[3] Homogenization is achieved by a mechanical device called a homogenizer.[3]