Makers provide liquidity to the exchange and “create” the market. Takers withdraw liquidity by executing existing orders on the exchange.
By placing an order that is executed immediately and will not go into the market book, the trader is a taker. Market order trades are always considered taker trades because market orders never enter the market order book.
When you place an order that falls partially or completely into the market order book (limit order), you are essentially “creating the market” and completing a maker trade.
The specification indicates the commission for one side of the transaction, i.e. the specified commission rate will be debited when opening a transaction and when closing it.