When the contract expires, speculators and others must close their positions. Speculators are used to increase the activity of the market.

Those who don't speculate can get physical objects, such as soybeans and corn, when the contract expires.

Hedging is to reduce risk,

For example, if I want to take two more hands of soybeans at the time of delivery, I will do two more hands, but I am afraid that soybeans will fall, so it will be better if soybeans go up, but it will not lose too much. This is hedging.

This is my understanding. ,,, may not be comprehensive.