Tuesday, June 12, 2007

Anatomy of a Web Address

URL (Universal Resource Locator, pronounced “you are ell”)

http - transfer protocol (type of information being transferred)
www.googleguide.com - website name, host name
googleguide - second-level domain name
com - top-level domain name
searchEngines - directory name (major category)
google - sub-directory name (sub-category)
searchLeader - file name (a file within the directory)
html - file format

Here’s a list of some common top-level domain names.

.edu - educational site (usually a university or college)
.com - commercial business site
.gov - U.S. government/non-military site
.mil - U.S. military sites or agencies
.net - networks, Internet service providers, organizations
.org - non-profit organizations and others

Because the Internet was created in the United States, “US” was not originally assigned to U.S. domain names; however, it’s used to designate American state and local government hosts, including many public schools, and commercial entities, e.g., well.sf.ca.us. The domain .ca represents Canada, unless it’s followed by .us, in which case it represents California.

Domain Codes State
.ca.us California
.nv.us Nevada
.tx.us Texas

Other countries have their own two letter codes as the top level of their domain names — although many non-US sites use other top-level domains (such as .com):

Domain Codes Country
.ca Canada
.de Germany
.dk Denmark
.jp Japan
.il Israel
.uk United Kingdom
.za South Africa

To limit results to a single site or domain, specify the site name (e.g., www.googleguide.com or googleguide.com) or a top-level domain name (e.g., .com or .edu) in Google’s domain selector.

Taken from: www.googleguide.com