Where CNAMEs show up
SaaS products ask you to CNAME www, shop, or docs at their infrastructure. CDNs do the same. The alias lets the vendor change IPs without making you edit A records. Keep chains short; each hop adds latency to every lookup.
The apex rule
A CNAME cannot sit beside other record types on the same name. The zone apex already has SOA and NS, so it cannot be a CNAME in standard DNS. Providers invent ALIAS or ANAME records to flatten that case. If this tool returns nothing for example.com, query A or AAAA instead. Comparison: CNAME vs A record.