Bare Domains are DNS records without www, also called Zone Apex, Naked Domain and Root Domain. To go live on section.io you need to setup a CNAME record pointing to the section.io platform.
Within the DNS system, you cannot use a CNAME for your bare domain (e.g. domain.com) and then define additional resource records for the same zone.
This means that if you were to setup a CNAME on your bare domain you would get unpredictable results and most likely break other records that also exist at the bare domain - such as MX records required for your email to work.
We recommend using section.io Hosted DNS so that you do not need to create a CNAME for your bare domain, as your DNS is already hosted with us. If you want to continue to use your current provider, there are 2 work arounds:
ANAMErecord type at the bare domain.
For technical background on CNAME’s and the bare domains see: RFC 1034 section 3.6.2.