In Forex, a pip is the smallest price move a currency can make—usually the 4th decimal place. The bid/ask spread is the difference between the price you can sell (bid) and buy (ask); it’s like the broker’s fee. And lot size just means how big your trade is—standard (100,000 units), mini (10,000), or micro (1,000). These three things help you figure out your costs, risks, and potential profits in a trade.