So here's your answer
Could and would are both used to talk about possible situations or event's. We use them to indicate when there's a possibility for something to happy, or to indicate the possibility of an event.
But, each of these (could and would) tell us something different. There is a slight difference..
Could is generally used when an action or event IS possible.
Meanwhile, would is used when we talk about a possible or imagined situation. It's often used when the possible situation
is not going to happen.