A lot in forex is the standard unit that traders use to measure the size of your trade. A standard lot is, in simple terms, 100,000 units of the base currency, which is the currency to the left in any pair. For example, 1 standard lot of USDJPY (here the USD is the base currency) equals 100,000 USD bought against the Japanese yen. The word standard contract is also sometimes used to refer to a standard lot.
Traders usually do not need to pay 100,000 USD to enter a 1 lot position. Instead, they rely on leverage from the broker and need to deposit only a portion of that amount. The higher the leverage, the smaller the amount they need to deposit.
Traders who have large accounts can trade standard lots, whereas traders with small...