It means that, unlike the telephone network for instance, no preliminary connection between two devices is needed before communications can start. It also means that many communications are possible at the same time with many partners. DNS has to be paid for and companies or individuals wanting a domain name have to identify themselves. Some public tools on the Net make it possible to retrieve the link between the domain name and the company as well as between the IP address and the domain name. A domain name is not in itself necessary for connecting a computer to the Internet.
Domain names are dynamic.
A limited amount of IP addresses exist at the present time. In this case, the IAP will typically keep a log file with the allocated IP address, subscriber's ID, date, time and duration of the address allocation. It can also be used as a firewall between an organisation and the Internet. It can especially guarantee that only authorised IP addresses can originate from a particular ISP . Some tools allow the net user to know the route between two points, but this can theoretically change every second, even during the transfer of a single web page.