Basics of derivative market

In option market the buyer of call option has rights to buy the product but there is no obligation. Put option buyer has rights to sell the product but there is no obligation. Once the contract was signed a premium will get from the buyer to seller. Exchange does MTM on daily basis to ensure the counter party risk.
In future market both buyer and seller make a deal on strike price, the exchange will get caution deposit from both buyer and seller, Exchange does MTM on daily basis to ensure counter party risk.