Internet (Network of network)
Internet is a network of networks. The Internet is technically a network of a wide variety of networks.
The internet is broken up into hundreds of thousands of smaller networks known as autonomous systems (AS) that exchanges route information via the Border Gateway Protocol (BGP)
Map of internet 1973:
The first top-level domain name defined for the Internet was ARPA
In the beginning, the global IP address registry was simply a list of IP address ranges, along with details of the organizations to which these had been allocated. Of course as more organizations joined the Internet, this list grew. Before long this important role was formalized as IANA – the Internet Assigned Numbers Authority. 1)
IANA could not scale to meet the demand for addresses or be able to service the wide range of different regional needs. In 1992, the Internet Engineering Task Force (IETF) recommended that Internet number resources be managed by subsidiary organizations at a regional level.
As a result, the Regional Internet Registries (RIRs) were established to assume this regional allocation and management role in cooperation with IANA.
What's internet anyway ?