What is a CNAME record?

A CNAME record is an ALIAS. This means that it will automatically redirect any "incoming" requests to the website you specify in the record.

Important

Because it's an ALIAS, you can't have any other record on the subdomain specified by a CNAME. The CNAME record overrides all other DNS record types, which will simply be ignored by DNS.

When should I use a CNAME record?

You use a CNAME record when you want a subdomain to point to another website.

Note

It's not possible to use a CNAME record for the Apex domain (naked, @, "example.com"). This must be done via a subdomain ("something.example.com"), usually www.  

https://en.wikipedia.org/wiki/CNAME_record

Here are a few examples:

blog 10800 IN CNAME exampleblogname.wordpress.com.

www 10800 IN CNAME exampleblogname.wordpress.com.

The CNAME examples above will allow visitors to see a WordPress Blog when they visit "blog.example.com" or "www.example.com".

Warning

The period (.) at the end of the "value" must be included in the record. If you don't include it, the record won't work.