2400:c780::/32 - TCB-NET
inet6num: 2400:c780::/32 netname: TCB-NET descr: Taiwan Cooperative Bank descr: No.77, Guanqian Rd., Zhongzheng Dist., descr: Taipei Taiwan 100 admin-c: HC1712-AP tech-c: HC1712-AP country: TW mnt-by: MAINT-TW-TWNIC mnt-irt: IRT-TWNIC-AP status: ALLOCATED PORTABLE last-modified: 2014-03-18T00:47:49Z 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.