Margin allows you to take a position for a larger stake in the market which is often the case with futures. In futures trading, you pay the margin upfront, held in an escrow account. It is a two-party contract, whereas the involvement of a broker in the margin trading makes it a tri-party deal. Further, in futures trading, the margin requirement is considerably lower than margin trading in equities, which requires you to pay 20-25 percent upfront.
Another significant point to remember is that in margin trading, you are required to pay interest on the sum borrowed. It impacts your total profit earning.