IPv6 is a new protocol which exists already and which presently operates simultaneously with IPv4. It will supersede IPv4 in the future.
IPv4 addresses are the ones known today, which consist of 4 numeric blocks divided by a dot. Due to the ever faster growing Internet structure and the continuously expanding number of devices connected to it, IPv4 addresses have become scarce by now. Technically, however, it is not possible to expand the number of IPv4 addresses, and therefore, a completely new protocol has been created with IPv6. This incorporates a substantially bigger number of addresses and is capable of coping with future challenges and requirements.