Internet and Domains-the existing generic top-level domains
A top-level domain (TLD) is one of the domains at the highest level in the hierarchical Domain Name System of the Internet. The top-level domain names are installed in the root zone of the name space. For all domains in lower levels, it is the last part of the domain name, that is, the last label of a fully qualified domain name.
Existing Generic TLDs
.com : companies, now broader
.edu : educational institutions
.gov : government institutions
.int : international organisations, e.g. Interpol
.mil : military organisations
.net : networking technologies, now broader
.org : non-profit organisations
.arpa : first ever domain, now technical use
.aero : air travel industry
.biz : business alternative to .com
.coop : co-operatives
.info : information, but open for general use
.museum : museums
.name : personal names – johnsmith.name
.pro : professionals, e.g. doctors
.asia: Asian websites
.cat : Catalan language
.jobs : employment websites
.mobi : mobile phones
.post : postal services
.tel : telecoms
.travel : travel
Source: Icann