Buy/sell orders which are waiting on the border of open orders until it matches properly is called "Open Order".
When order you placed is matched by other users on the price you demand, buy/sell transaction occurs. When there are no order matches to order's price or whole of order amount is not matched, left amount continues to be listed as Open Order. On Koinim, Open Order board of every crypto-currency is listed under its own buy/sell page.
In case of cancelling your orders, click "X" sign on Open Orders board, at the side of crypto-currency you are transacting.