Difference between Rasa core and Rasa nlu

Question

I tried to understand about rasa from official documentation of Rasa core and Rasa nlu but not able to deduce much. What I am able to understand is

Rasa core is

Answer 1

To explain in simple terms Rasa NLU uses NLP (Natural Language Processing) to understand what you tell the bot.

It understands what you say and matches it to some intent that you have defined.

Rasa Core on the other hand handles the conversation flow. The stories markdown file lists the intents and the actions for them.

Hence when the NLU gives the intent, the Core performs the action corresponding to it and the bot replies with that action.