A trade order gets the ​maker​ fee if the trade order is not matched immediately with an opposing order already on the order book​.

When using a Limit order, this is where you choose the price that your order will execute, thus, incurring a maker fee. This would be the opposite of a Market order, where you accept the best available price, and thus incur a taker fee.

Limit orders can still execute as market order if the price you select is not placed on the correct side of the order book, read here on how to set your price for a Limit order.

You can use the post limit order option to ensure that your limit order will be placed in the correct side of the order book, and get the maker fee, or else it will get cancelled. (No order is placed at all)

A trade order gets the ​taker​ fee if the trade order is matched immediately against an order already on the order book.

All Market orders will execute immediately, and will incur the taker fee. This includes conditional orders that execute as a market order, such as a stop loss order and a take profit order.

Limit orders can also execute immediately, thus, incurring a taker fee. When placing a Limit order with the intention of avoiding taker fees, it is important to know how to set the price of your Limit order.