Imagine this: You’re building some kind of a chat system. For every message from the user, you want to figure out what the message is about. Is the user asking a question? Or does the user asking to perform a specific action? Or is the user talking about something completely irrelevant to your system?

What we are doing here is detecting the “intent” of the user’s message. Think of the intent as a set of predefined categories like QUESTION, ACTION1, ACTION2, OUT_OF_DOMAIN.