Difference between CNAME and SUBDOMAIN

Question

What is the difference between a CNAME and a Subdomain?

I understand that the a cname (the left side of a domain) can point to the domain, so you can two different urls point to the same address, ie.

ex1.mydomain.com - if setup as a CNAME can return the IP of mydomain.com

If ex1.mydomain.com is setup as a subdomain, does it have a different IP?

Another question is what should the ideal setup be in this situation:

I have IP1:80 for a web app

I have IP2:80 for another app

Can I point both of these IPs to the same A record, with perhaps a different cname or subdomain?

Thanks for any help?

Answer 1

CNAME is agnostic about name topology - it simply provides a way to alias a lookup for one name into a lookup for another name. So it may be in a subdomain context, or not.

Your second question doesn't make any sense to me. An A record maps from a domain name to (a single) IP address. So normally, in this situation, you'd have two domain names with an A record for each.