Limit order
A pending order that fills at the set price or better. The price is guaranteed, the fill is not.
A buy limit goes below the current price, a sell limit above it; it fills if price comes there. Limit orders add liquidity to the order book and at some brokers trade at a lower commission.
Traders who want to enter at a set level on pullbacks use limit orders; the downside is that price may leave without touching the level.