From Traderpedia

Definition: An order in which the customer sets a maximum price he is willing to pay as the buyer or a minimum price he is willing to accept as the seller.

Th limit order ensures that a person will never pay more for the security (or sell it for less) than whatever price is set as the limit. This is one of the three most common types of orders, the others being market order and stop order. Limit orders can also be placed as part of an OCO bracket order.