The TRAIN button activates the process of training the bot. After you have uploaded your knowledge base, labeled new queries or edited a FAQ article, make sure you pressed the TRAIN button! Without it, your edits won't take effect.
Every Machine Learning algorithm has a training stage when it learns from the examples you gave it. It may take the bot a minute or so to digest the new examples. The button remains red, and the spinner keeps spinning while the training goes on. It will turn green when finished. Green means the training is done and your bot is up-to-date.