Links between A, CNAME and DNS Name

Question

I am confused because I have used A and CName successfully sometimes and sometimes not depending on the registrar so:

1°) To be able to change A or CNAME on a registrar, must I use their DNS name servers or can I keep any DNS name servers ?

2°) When I add an IP to CName, do I have to do so also to A otherwise it won't work ?

Answer 1

1. Yes you need to use thier name servers to be able to use their control panel to change names.

2. A CNAME is an alias and cannot point to an IP address it can only point to a A record which in turn points to the IP address