Matching Orders is the process of identifying and effecting a trade between equal and opposite requests for a security (i.e., a buy and a sale at the same price). Order matching is how many exchanges pair buyers and sellers at compatible prices for efficient and orderly trading.In other words, when you want to buy shares of Apple stock, there's someone on the other side of that trade who wants to sell their shares. The exchange matches up those two orders so that both parties can complete their trades.