Are financial contracts that allow you as the buyer to agree on a price for an instrument in the present, which will be exchanged once in an agreed future that varies based on the length of the contract.

Futures are simply explained contracts where two parties agree to exchange an underlying instrument at a fixed price sometime in the future.
It gives the buyer the obligation to buy the underlying instrument and the seller the obligation to sell the underlying instrument for the predetermined price at or before the term of the contract.