Users create this software themselves and often overlook how important it is. In some types of embedded systems, the application software and the operating system software may be indistinguishable to the user, as in the case of software used to control a VCR, DVD player or Microwave Oven.
You can jam milk through pretty small holes with force like that. Before homogenization, fat globules range in size from 1-10 microns (a micron = ~0.00004 inch). After, the size range is reduced to 0.2-2 microns.
Homogenization is an entirely separate process that occurs after pasteurization in most cases. The purpose of homogenization is to break down fat molecules in milk so that they resist separation. Without homogenization, fat molecules in milk will rise to the top and form a layer of cream.