The Control of a card is the number indicated in the lower right corner of the card on normal cards, and a little bit higher on split cards. It is the value used for Control Checks (abbreviated to CC) and various other abilities in the game. A control value currently oscillates between 1 and 6. Usually, assets and foundations will have higher control values than actions and attacks, however, there are exceptions - Soul Spark, for example, is an attack with a control value of 4.
Control Checks Edit
Control Checks are vital to the progression of the game. It is how a player plays cards into his card pool. In order to do so, the control value must be equal or higher than the difficulty plus progressive difficulty of the card he wishes to play. If that is the case, the control check is considered successful and the turn may continue. If not, the control check is considered failed unless the player who failed the control check chooses to commit foundation cards in his staging area to make up for the numerical difference between the control check and the difficulty of the card played.
To play Super Deadly Ninja Bees, you need a control check of 6 or higher as it has a difficulty of 6. You perform a control check with Loving Devotion, which has a control of 6. You have therefore passed the check. If you would have checked a Super Deadly Ninja Bees, however, you would have a control of 3. You would therefore need to commit 3 foundations to make up for the difference in the check and the difficulty.