Commodity futures generally have referred to physical commodities -- grains, livestock, lumber, coffee, sugar, and the like. During the early history of "commodity exchanges," to which all futures exchanges were referred, this made perfect sense; most futures contracts were, indeed, physical commodities. However, many market participants, by habit, term all futures products as "commodity futures" -- in other words, as a class of "investment."
In recent years, many exchanges have made a clear distinction between their product offerings, differentiating between physical "commodity futures" and their dominant "financial futures," which include futures and options on foreign currencies, interest rate (Eurodollar, Treasuries, swaps, etc.) and stock index products (S&P 500, Russell and Dow indexes, etc.).
In addition, "energy futures" comprising such products as crude oil and heating oil, and "metals futures" (the metals)," like silver and gold, have become additional futures classifications.