When I started learning about the Internet, I found out that there are Network Information Centers (NIC) for the various geographical regions. At that time, I only knew APNIC (Asia Pacific), ARIN (North America), RIPE NCC (Réseaux IP Européens Network Coordination Centre - Regional Internet Registry (RIR) for Europe, the Middle East and parts of Central Asia) and LACNIC (Latin America and Caribbean Network Information Centre). Now, there's more!
What do I use it for? Mainly, I use it to find out what companies are certain IP addresses from - using the respective registry's whois service.
Whois for various NICs:
In 2017, with the release of Delphi 10.2 Tokyo, Embarcadero introduced a specialized implementation of the Observer pattern into the System.Classes unit. While it has been in the wild for 9 years, it remains a "hidden" architecture for many, primarily because it serves as the invisible engine behind LiveBindings. Other than live bindings, you can also use the Observer pattern as a way to update component settings to the Windows registry, an .ini file, or persist it elsewhere.
System.Classes