The way *I* typically use them...
[greg@lanai WG3 ~]$ dig uno.gregfolkert.net
; <<>> DiG 9.2.4 <<>> uno.gregfolkert.net
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62625
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;uno.gregfolkert.net. IN A
;; ANSWER SECTION:
uno.gregfolkert.net. 1571 IN A 208.64.37.170
;; Query time: 2 msec
;; SERVER: 192.168.204.104#53(192.168.204.104)
;; WHEN: Mon Oct 1 21:22:04 2012
;; MSG SIZE rcvd: 53
CNAME is any other name I give it: www.gregfolkert.net, mail.gregfolkert.net or just gregfolkert.net
[greg@lanai WG3 ~]$ dig www.gregfolkert.net
; <<>> DiG 9.2.4 <<>> www.gregfolkert.net
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 29876
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;www.gregfolkert.net. IN A
;; ANSWER SECTION:
www.gregfolkert.net. 1800 IN CNAME uno.gregfolkert.net.
uno.gregfolkert.net. 1800 IN A 208.64.37.170
;; Query time: 144 msec
;; SERVER: 192.168.204.104#53(192.168.204.104)
;; WHEN: Mon Oct 1 21:18:15 2012
;; MSG SIZE rcvd: 71
CNAME for my nearly static IP Address at home, owned by comcast:
archer.gregfolkert.net is a CNAME for c-98-209-73-13.hsd1.mi.comcast.net.
[greg@lanai WG3 ~]$ dig archer.gregfolkert.net
; <<>> DiG 9.2.4 <<>> archer.gregfolkert.net
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 49508
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;archer.gregfolkert.net. IN A
;; ANSWER SECTION:
archer.gregfolkert.net. 1800 IN CNAME c-98-209-73-13.hsd1.mi.comcast.net.
c-98-209-73-13.hsd1.mi.comcast.net. 5278 IN A 98.209.73.13
;; Query time: 52 msec
;; SERVER: 192.168.204.104#53(192.168.204.104)
;; WHEN: Mon Oct 1 21:21:14 2012
;; MSG SIZE rcvd: 101
If you notice there are two lookups.