Margin and leverage are financial concepts often used interchangeably, but they represent different mechanisms in trading and investing.

Margin refers to the amount of money that an investor borrows from a broker to buy securities. It's a loan from the broker, and the margin account allows the investor to buy more securities than they could with their own funds alone. When trading on margin, the investor must deposit a percentage of the total investment, known as the initial margin. For example, if an investor wants to purchase $10,000 worth of stock on a 50% margin, they need to put up $5,000, and the broker lends the remaining $5,000.

Leverage, on the other hand, is the use of borrowed capital to increase the potential return on investment. It amplifies both gains and losses. Leverage is often expressed as a ratio. For instance, a 2:1 leverage means that for every dollar the investor puts in, they can control two dollars’ worth of assets. Higher leverage allows for greater exposure to the market with a smaller initial investment. However, it also increases the risk of substantial losses if the market moves against the investor's position.

Margin is the borrowed money used to purchase securities, while leverage is the strategy of using borrowed funds to increase potential returns, magnifying both profits and losses.