Order types: limit, market, stop

There are two big families of orders, and the tension between them is the whole mechanics of the market. Passive orders wait in the book; aggressive orders come to take them. All the order types a platform offers (limit, market, stop, stop limit, bracket) fall into one family or the other at the moment they execute.

Understanding this distinction changes the way you look at every transaction. When volume scrolls by, the question is not “how much”, but “who took the initiative”.