First of all we need to understand that IANA Internet Assigned Numbers Authority is the main body that distributes IP to all over the world.

The AfriNIC is the Internet Number Registry for Africa

Mainly associated with providing internet IP over the african region.

The ARIN the American Registry for Internet Numbers

Mainly associated with providing internet IP over the american region.

The APNIC the Asia Pacific Network Information Centre.

Mainly associated with providing internet IP over the asia pacific region.

The LACNIC is Latin America and Caribbean Network Information Centre.

Mainly associated with providing internet IP over the latin america  and caribbean region.

The RIPE NCC is Reseaux IP Europeens Network Coordination Centre.

They all provides IP National Internet Registries after that the IP are assigned or passed to the Local Internet Registeries.

Then after that the IP are purchased by the ISP Internet Service Provider.

Then internet is accessed by the end user.

This is how the internet IP is purchased and assigned to the people .