CloudFlare works in two modes: Basic mode and advanced mode.
With the basic mode, you do not have to worry about making changes to your name server or management of DNS records. All you need to do is to access your cPanel to enable CloudFlare – no other changes on your part required.
Advanced mode requires changing the name servers, so it is only recommended for advanced users who are not able to create the redirects that are necessary for the basic mode. Once the name servers have been changed, future adjustments will have to be made to the zone file specific to CloudFlare via cPanel.
If you tried to add a domain in advanced mode, but want to switch to basic, you must first remove the domain from CloudFlare dashboard.