Different types of miles you can earn:
With Award miles you will be able to get award tickets, stay at hotels, rent a car. There is a validity period of 20 months for Award Miles> you can extend this validity period by making a flight booking with KLM, Air France, or SkyTeam member airlines on paid basis at least once every three year.
The Level miles will provide you the option to move higher level of Flying Blue membership. You can move from Ivory to Silver, Gold, or Platinum membership level. The level miles are valid only for one calendar year.