inet6num: 2404:f080::/32 netname: RUNSYSTEM-VN descr: GMO RUNSYSTEM JSC descr: 118 Nguyen Ngoc Nai, Khuong Mai, Thanh Xuan, Hanoi admin-c: NVT15-AP tech-c: LQL7-AP remarks: send spam and abuse report to email@example.com country: VN mnt-by: MAINT-VN-VNNIC mnt-lower: MAINT-VN-VNNIC mnt-irt: IRT-VNNIC-AP status: ALLOCATED PORTABLE last-modified: 2016-04-29T02:49:09Z source: APNIC
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.