Adaptive capacity is the capacity for a system to deal effectively with change through adapting to it. Adaptive capacity  is a product of the system having many different responses to any given perturbation. And this is enabled by the system having experienced and survived some perturbation and stored that state to ensure its capacity to adapt to it in the future, for example, this is how the immune system works. Whereas resistance means trying to externalize change by preventing it, adaptative capacity involves internalizing it, i.e. being able to change with the environment.