Leverage trading, or trading on margin, means that you are not required to put up the full value of a position. As a result you can open a significantly larger position than you would be able to if you needed to fund your trade in full. Trading on leverage increases the potential for profit, and allows traders to participate in markets that would otherwise be cost prohibitive, but also increases the risks, and so the potential for losses.
Leverage for spot gold and silver trading is default set at 100:1. This means that for every $1 you have in your account balance, you can trade $100 worth of a position.