First internet connection was established in 1969 which was advancement of computer network by ARPA commissioned in 1968.
Different protocols were developed with course of time. Between 1977 and 1979 IPv 0-3 were used. IPv 4 came on front in 1983 and in 1992 work began on IP next generation (IPng) which became IPv6.
IPv6 has 128 bit addresses which means more no. of devices can be connected at a time and it also attempted to fix some of the inherent issues in IP like in security concerns.
The basic process involved in working of networks can be seen in this amazing video of Tomas Stephanson.