What is free and what not

Hi, I am very confused. I read that Rasa is free and open source, but there is Rasa X Rasa Pro and Rasa Community as well as Rasa Open Source and something about Rasa core.

Now what is what. I just started here. There were also pages which said that Rasa is discontinued or will not be updated anymore.

Please help me a understanding this mess, my understanding of english is not the best.

Thank you