IPv4

An IPv4 address is a 32 bit decimal dot separated number used for identifying computers on a network. They are formatted with up to 3 digits per octet boundary, and each address has 4 octet boundaries. EX: 23.133.248.1

Currently, and for a long time there has been a large scale shortage of IPv4 addresses, leading to the need for things like NAT and CG-NAT, which is why IPv6 currently being rolled out to at some point replace IPv4. Obtaining v4 addresses due to the mass shortage of them is very expensive, they generally cost upwards of $100 a month for a single range of v4 IPs.