Web Service - Create User

Hi Everyone

I was reading a discussion from 2012 about creating a new user in moodle using Web Service.  I am trying to find clarification and possibly instructions on this topic.  I would like to know first - is it possible, can you create a new user with web service?  If so, how can it be done and what can trigger the occurrence?  I would like to trigger this from my website or Paypal if possible.  

Next, is it possible then to enroll the newly created user into a specific course?

Thank you in advance for your help in this,