When faced with the need to take action we can deal with it one of two ways: First, we can react. This is the knee-jerk, after the fact, go fix it because we let it get broken. When Hurricane Katrina hit the Gulf Coast, there were all kinds of reactions, but not a planned response.
Second, response is dealing with the situation in a planned, creative way. People anticipate and are prepared so that when action is required, resources are mobilized and ready. An emergency can then be treated as an expected event, not a surprise. A trained medical response team, responds rather than reacts.