In general, commodity ETFs focus on physical goods that are defined as commodities. On the other hand, stock ETFs focus on exposure to shares included in the fund. Many commodity ETFs offer exposure to physical commodities or to futures contracts of commodities. Stock ETFs offer exposure to stocks or futures contracts of stocks. However, some commodity ETFs are also stock ETFs. For example, if an equity-backed ETF focuses on companies that are involved with the extraction of commodities, they can be viewed as commodity ETFs.