The currency market, or foreign exchange market ("forex"), was created to facilitate the exchange of currency that becomes necessary as the result of foreign trade. That is, when an entity in one country sells something to an entity in another country, the seller earns that foreign currency. When China sells t-shirts to Walmart, for example, China earns US dollars. When Toyota wants to build a factory in the US, it needs dollars. It may get those from its local bank, which in turn will obtain them in the international currency market. This market exists to facilitate these types of exchanges.

A sampling of terms defined includes: active premium, aggregation, angel financing, asset allocation, backwardation, benchmark, bridge loan, capital structure arbitrage, coefficient of determination, commodity option, convertible arbitrage, deferred futures, discretionary trading, distressed debt, enumerated agricultural commodities, extrinsic value, follow-on funding, hedge ratio, interdelivery spread, long short equity, modified value-at-risk, offshore fund, piggyback registration, social entrepreneurship, systematic trading, tracking error, underlying futures contract, venture capital method, and weather premium.
For example: Tomatoes are cheap in July and will be expensive in January, you can’t buy them in July and take delivery in January, since they will spoil before you can take advantage of January’s high prices. The July price will reflect tomato supply and demand in July. The forward price for January will reflect the market’s expectations of supply and demand in January. July tomatoes are effectively a different commodity from January tomatoes.
Many day traders who trade futures, also trade options, either on the same markets or on different markets. Options are similar to futures, in that they are often based upon the same underlying instruments, and have similar contract specifications, but options are traded quite differently. Options are available on futures markets, on stock indexes, and on individual stocks, and can be traded on their own using various strategies, or they can be combined with futures contracts or stocks and used as a form of trade insurance.

Options are available as either a Call or a Put, depending on whether they give the right to buy, or the right to sell. Call options give the holder the right to buy the underlying commodity, and Put options give the right to sell the underlying commodity. The buying or selling right only takes effect when the option is exercised, which can happen on the expiration date (European options), or at any time up until the expiration date (US options).
As an example, let's say a farmer is expecting to produce 1,000,000 bushels of soybeans in the next 12 months. Typically, soybean futures contracts include the quantity of 5,000 bushels. The farmer's break-even point on a bushel of soybeans is $10 per bushel meaning $10 is the minimum price needed to cover the costs of producing the soybeans. The farmer sees that a one-year futures contract for soybeans is currently priced at $15 per bushel.

The potential home buyer would benefit from the option of buying or not. Imagine they can buy a call option from the developer to buy the home at say $400,000 at any point in the next three years. Well, they can—you know it as a non-refundable deposit. Naturally, the developer wouldn’t grant such an option for free. The potential home buyer needs to contribute a down-payment to lock in that right.
So, call options are also much like insurance - you are paying for a contract that expires at a set time but allows you to purchase a security (like a stock) at a predetermined price (which won't go up even if the price of the stock on the market does). However, you will have to renew your option (typically on a weekly, monthly or quarterly basis). For this reason, options are always experiencing what's called time decay - meaning their value decays over time.