Domain NamesDomain Names

What is the Internet?What is the Internet? The The InternetInternet is a global system of is a global system of

interconnected interconnected computer networkscomputer networks that that use the standardized use the standardized Internet Protocol SuiteInternet Protocol Suite (TCP/IP) to serve (TCP/IP) to serve billions of users worldwide. It is a billions of users worldwide. It is a network network of networksof networks that consists of millions of that consists of millions of private and public, academic, business, private and public, academic, business, and government networks of local to and government networks of local to global scope that are linked by global scope that are linked by coppercopper wires, wires, fiber-opticfiber-optic cables, cables, wirelesswireless connections, and other technologies. connections, and other technologies. (http://en.wikipedia.org/wiki/Internet)(http://en.wikipedia.org/wiki/Internet)

What is the Internet?What is the Internet?

A network of A network of computers computers connected to connected to each other. each other.

How do they Connect?How do they Connect?

These computers needed to These computers needed to know which computer they know which computer they were connecting to, so each were connecting to, so each computer was given a unique computer was given a unique number – an IP (Internet number – an IP (Internet Protocol) number. Ex. Protocol) number. Ex. 121.245.078.2121.245.078.2

Greater numbers of users networking Greater numbers of users networking with each other created a demand for an with each other created a demand for an easier system and one that was less easier system and one that was less confusing. confusing.

In the mid 1980’s the Domain Name In the mid 1980’s the Domain Name System was implemented and the initial System was implemented and the initial top-level domain names, top-level domain names, including .com, .net, and .org, were including .com, .net, and .org, were introduced. introduced.

Suddenly 121.245.078.2 became Suddenly 121.245.078.2 became 'company.com'. 'company.com'.

Top Level Domain NamesTop Level Domain Names

The initial set of top-level domains The initial set of top-level domains was established. These were was established. These were considered "general purpose considered "general purpose domains" domains"

..comcom, ., .eduedu, ., .govgov, ., .milmil, ., .orgorg. The .. The .netnet domain was added with the first domain was added with the first implementation of these domains.implementation of these domains.

The Original Top Level The Original Top Level DomainsDomains

.com - .com - commercial organizations, commercial organizations, but unrestricted but unrestricted

.edu - .edu - educational establishments educational establishments

.gov – .gov – gov’t entities within the gov’t entities within the U.S.U.S.

The Original Top Level The Original Top Level DomainsDomains

.mil – the U.S. military.mil – the U.S. military

.org – organizations, now .org – organizations, now unrestrictedunrestricted

.net - .net - initially intended to be used initially intended to be used only for network providers, now only for network providers, now unrestrictedunrestricted

Parts of a Domain NameParts of a Domain Name

A A domain namedomain name usually consists of usually consists of two or more parts (technically two or more parts (technically labelslabels), which are separated by dots, ), which are separated by dots, such as example.com.such as example.com.

The rightmost label is the The rightmost label is the top-level domaintop-level domain (for example, the (for example, the address www.example.com has the address www.example.com has the top-level domain com). top-level domain com).

Various Levels of Domain Various Levels of Domain NamesNames

http://www.ci.west-allis.wi.ushttp://www.ci.west-allis.wi.us

Country CodesCountry Codes

A A country code top level domain country code top level domain is generally used or reserved for is generally used or reserved for a country.a country.

.us – United States .us – United States .ca - Canada.ca - Canada

.mx – Mexico.mx – Mexico .pr – Puerto .pr – Puerto RicoRico

Additional Domain Additional Domain NamesNames

With the rapid growth of the With the rapid growth of the internet, additional top level internet, additional top level domains have been added domains have been added over the years.over the years.

We no longer have the original We no longer have the original 6 – 6 – the list is much longer.the list is much longer.