A commodity is a basic good used in commerce that is interchangeable with other goods of the same type. Commodities are most often used as inputs in the production of other goods or services. The quality of a given commodity may differ slightly, but it is essentially uniform across producers.
When they are traded on an exchange, commodities must also meet specified minimum standards, also known as a basis grade. They tend to change rapidly from year to year.
The basic idea is that there is little differentiation between a commodity coming from one producer and the same commodity from another producer. A barrel of oil is basically the same product, regardless of the producer.
By contrast, for electronics merchandise, the quality and features of a given product may be completely different depending on the producer. Some traditional examples of commodities include the following:
More recently, the definition has expanded to include financial products, such as foreign currencies and indexes. Technological advances have also led to new types of commodities being exchanged in the marketplace. For example, cell phone minutes and bandwidth.
The sale and purchase of commodities are usually carried out through futures contracts on exchanges that standardize the quantity and minimum quality of the commodity being traded. For example, the Chicago Board of Trade stipulates that one wheat contract is for 5,000 bushels and states what grades of wheat can be used to satisfy the contract.
There are two types of traders that trade commodity futures. The first are buyers and producers of commodities that use commodity futures contracts for the hedging purposes for which they were originally intended. These traders make or take delivery of the actual commodity when the futures contract expires. For example, the wheat farmer that plants a crop can hedge against the risk of losing money if the price of wheat falls before the crop is harvested. The farmer can sell wheat futures contracts when the crop is planted and guarantee a predetermined price for the wheat at the time it is harvested.
The second type of commodities trader is the speculator. These are traders who trade in the commodities markets for the sole purpose of profiting from the volatile price movements. These traders never intend to make or take delivery of the actual commodity when the futures contract expires.
Many of the futures markets are very liquid and have a high degree of daily range and volatility, making them very tempting markets for intraday traders. Many of the index futures are used by brokerages and portfolio managers to offset risk. Also, since commodities do not typically trade in tandem with equity and bond markets, some commodities can also be used effectively to diversify an investment portfolio.
Commodity prices typically rise when inflation accelerates, which is why investors often flock to them for their protection during times of increased inflation—particularly unexpected inflation. As the demand for goods and services increases, the price of goods and services rises, and commodities are what's used to produce those goods and services. Because commodities prices often rise with inflation, this asset class can often serve as a hedge against the decreased buying power of the currency.Source: https://www.investopedia.com/terms/c/commodity.asp