What is a cname?
Canonical name for an alias. CNAME-records are domain name aliases. Often computers on the Internet have multiple functions such as web-server, ftp-server, chat-server etc. To mask this, CNAME-records can be used to give a single computer multiple names (aliases). For example computer “xyz.com” may be both a web-server and an ftp-server, so two CNAME-records are defined: “www.xyz.com” = “xyz.com” and “ftp.xyz.com” = “xyz.com”. Sometimes a single server computer hosts many different domain names (take ISPs), and so CNAME-records may be defined such as “www.abc.com” = “www.xyz.com”. The most popular use the CNAME-record type is to provide access to a web-server using both the standard “www.domain.com” and “domain.com” (without the www). This is usually done by creating an A-record for the short name (without www), and a CNAME-record for the www name pointing to the short name.
Cname is short for canonical name. A cname is a DNS hostname which, instead of mapping to an IP address, maps to another DNS hostname. When a nameserver recieves a request to convert a cname into an IP address, it responds with the IP address of the hostname to which the cname maps. As an example, consider the hostname quads.uchicago.edu. quads.uchicago.edu is a cname for harper.uchicago.edu. harper.uchicago.edu has address 128.135.12.7 Thus, a request for the IP address of quads.uchicago.edu will yield 128.135.12.7.
CNAME records are domain name aliases. The most popular use of the CNAME record type is to provide access to a web server using both the standard “www.domain.com” and “domain.com” (without the www). This is usually done by creating an A record for the short name (without www), and a CNAME record for the www name pointing to the short name. A CNAME record should always point to an A record to avoid circular references.
