There will usually be many candidate intents which can fire at any given point in the conversation. But if we are building a chatbot to achieve specific goals, we would like only a set of specific intents to fire.
Let us call these target intents.
Clearly, target intents are a function of where you are in the conversation. A target intent for the first step in your conversation is almost certainly not going to be a target intent for a future step, because otherwise we would be regressing during the conversation rather than moving forward.
In the video below, I explain target intents.