inetnum: 2001:12f8:4::/47 aut-num: AS11644 abuse-c: FAN owner: Núcleo de Inf. e Coord. do Ponto BR - NIC.BR ownerid: 05.506.560/0001-36 responsible: Demi Getschko country: BR owner-c: FAN tech-c: FAN created: 20171129 changed: 20171129 nic-hdl-br: FAN person: Frederico Augusto de Carvalho Neves e-mail: firstname.lastname@example.org country: BR created: 19971217 changed: 20171103
IP address ranges, or netblocks, are groups of related IP addresses. They are usually represented as a base IP address, followed by a slash, and then a netmask which represents how many IP addresses are contained within the netblock. This format is known as CIDR. You'll also sometimes see netblocks given as a start ip address, and an end ip address, or an ip address range.
Traffic works its way around the internet based on the routing table, which contains a list of networks and their associated netblocks.