Limit order
An exchange order that names your price and waits, filling only at that price or better, possibly in pieces, possibly never.
A limit order tells an exchange: this price or better, or nothing. Bid £99 for a coin asking £100 and your order joins the order book and waits. If the market comes down to you, it fills. If the market climbs instead, it sits there indefinitely, buying nothing the whole way up.
The waiting has consequences worth knowing. Crypto trades 24/7, so a resting order can fill at 4am on a weekend spike while you sleep. Fills can be partial: five coins bid for, two bought, the remainder still working. Most exchanges default to good till cancelled, which means an order you forgot about can execute weeks later. Cancelling costs nothing before it fills, so a periodic glance at the open-orders tab is a good habit.
The trade-off against a market order is exact: you gain certainty about price and give up certainty about execution. A limit order also keeps its one promise in a crash. You will not pay above your number, although you can be filled at £99 while the market is on its way to £80.
Our market orders versus limit orders guide runs the whole comparison on a worked example.