This category and its subcategories are concerned with the recognition, handling, and processing of materials and components that have more than one constituent part. The systems, machinery, and equipment, as well as the various ancillary products they employ, are designed to analyze, categorize, sort, and separately store or dispose of the different parts. The end results can vary, but they will invariably comprise at least a couple of distinct elements. Note: Sites related to joining or merging materials and their parts are more properly indexed in the Process_Equipment/Mixers_and_Dispensers category. Additional note: On the whole, sites concerned with the removal of contaminants in air, gases, and water belong in the Process_Equipment/Filtering category. (This differentiation is based on a recognition that a single cleansed/purified element/condition is the end result of filtering, whereas a separating process [as already implied above] produces at least two parts of the original whole.) At the same time, however, there's something of a fine distinction when it comes to oil/water, liquid/solid, and wastewater treatment systems, which invariably result in two reusable elements and are therefore more properly allocated to this Separators category.