The term contract can be a little off-putting but it is mainly used because, like a contract, a has an expiration date. You don’t have to hold the contract until it expires. You can cancel it anytime you like. In fact, many short-term traders only hold their contracts for a few hours – or even minutes!
For example, I you are
The nearer (to expiration) contracts are usually more liquid, i.e. there are more traders trading them. Therefore, prices are truer and less likely to jump from one extreme to the other. Other contract might trading in premium or discount and with wide bid ask spread means you have to pay more than current contracts.
Neither is there a limit on the you can trade (within reason – there must be enough buyers or sellers to trade with you.) Many larger traders/investment companies/banks, etc. may trade thousands of contracts at a time!
Futures contracts are available on different kinds of assets – stocks, indices, commodities, pairs and so on.