Limit orders
A limit is a price you are willing to pay (buy) or receive (sell). If it does not cross, it rests on the book.
Buys
You bid at a limit price. It fills only at that price or better (lower). If the market is already through your bid, it can fill immediately against the other side / house rules. If not, it rests.
Sells
You offer at a limit. It fills at that price or better (higher), or it rests.
Cancelling
Open orders tab → cancel. Locked funds return to available. There is no fee to cancel.
Resting orders and the oracle
When the live rate moves, resting limits are re-checked. A bid that becomes marketable can fill without you clicking again. That is how a real book works — not a bug.