Margin is the amount of a trader's funds required to open a new position. Margin is estimated based on the size of your trade, which is measured in lots.
A standard lot is 100,000 units. We also provide mini lots (10,000 units), micro lots (1,000 units) and nano lots (100 units). The greater the lot, the bigger the margin amount.
Margin allows you to trade with leverage, which, in turn, allows you to place trades larger than the amount of your trading capital. Leverage influences the margin amount too.