AS1221 Telstra Pty Ltd
2001:360::/32 - V6TELSTRAINTERNET-AU-20011211
inet6num: 2001:360::/32 netname: V6TELSTRAINTERNET-AU-20011211 descr: Australian National Telephony and IP carrier country: AU org: ORG-TC6-AP admin-c: SM249-AP admin-c: PL183-AP tech-c: SM249-AP tech-c: PL183-AP status: ALLOCATED PORTABLE remarks: from /35 to /32 notify: firstname.lastname@example.org mnt-by: APNIC-HM mnt-lower: MAINT-AP-TELSTRA mnt-irt: IRT-TELSTRA-AU last-modified: 2017-09-26T23:28:55Z 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.