These are the conditions to be met in order to be able to convert bonus money into real money. The bonus balance is converted into real money once the stake conditions are met, within the defined completion period.
To meet these bet conditions, you must re-stake the sum of the bonus received, the number of times defined in the current bonus conditions. The bet conditions are described for each bonus in the Bonus and promotions page.
You can see the progress made in fulfilling the bet conditions in your player account under the My bonuses section.