Limit order: execute a trade at a specified price or better (limit price).
A limit order to buy would be at the limit price or lower, and a limit order to sell would be at the limit price or higher.
Limit orders are used by traders who have decided on the price at which they are willing to trade.
As soon as you create an order of this type, a specified amount of funds is being reserved on your account. You can see it on your account in the "On orders" column.
Limit orders appear on the order book.
Stop limit order: create a limit order at a specific price (stop price)
When the stop price is reached, a stop-limit order becomes a limit order. So you're specifying two prices: stop price, reaching thereof triggers the creation of a limit order, and a limit price for that limit order.
This type of order doesn't require reserved funds and will not appear in the order book before it's activated.
Subtypes of limit orders
Good-Till-Cancelled - lasts until the order is completed or canceled.
Day - automatically expires if not executed on the day the order was places. A day ends at 00:00 UTC time.
Good-Till-Date/Time - automatically expires at the specified date and time.
Fill-Or-Kill - must be executed immediately in its entirety; otherwise the entire order will be cancelled (i.e., no partial execution of the order is allowed).
Immediate-Or-Cancel - must be executed immediately. Any part of an IOC order that cannot be filled immediately will be canceled.
Note: to find out how to cancel your order, please proceed to How to cancel my orders.