There are 4 types of resources in Civilization War: Food, Lumber, Stone and Iron.
All are used for various game aspects development, including but not limited to: building construction and upgrade, troops training, healing, etc.
Food and Lumber are available early in the game, while Stone and Iron are unlocked on further stages.
All resources within the game are divided into the common and safe categories.
Safe Resources have the following qualities:
1. These are resources acquired from the Resource Chests.
2. These resources are protected in the Castle Depot but cannot be moved to the Alliance Depot.
3. They are not used as soldiers' food consumption.
4. They cannot be looted by enemies and are not displayed in scout reports.
The bar in the top right corner of the screen shows a total amount of resources you possess (common+safe).
To see the actual amount of safe resources, you should press the resource bar. Number is displayed in the bottom left corner for each type.