The resource pool can be used to release resources for the team. These released resources can be used to increase the attack or defense.
Imagine you can't do anything in your turn and you don't have any good cards in your hand. You are allowed to put one of your buffer cards into the resource pool per turn.
As soon as you or a fellow player want to attack or have to defend a node, you can increase its strength using the resource pool.
Simply take the desired number of cards from the pool and throw them into the archive.
Only the number of cards used plays a role here, not their values.