IP Address | What is IPv4’s history?

What is IPv4’s history?

                      IPv4 has just over four billion unique IP addresses. It was developed in the early 1980s and served the global Internet community for more than three decades. But IPv4 is a finite space, and after years of rapid Internet expansion, its pool of available unallocated addresses has been fully allocated to Internet services providers (ISPs) and users. Only 3.7 billion IPv4 addresses are usable by ordinary Internet access devices. The others are used for special protocols, like IP Multicasting. Almost three and a half billion addresses was enough for the experiment that the Internet started as in the 1980s, but it is not enough for a production network in today’s world, with its population of almost seven billion people.