2a03:c980:4::/48 - ZAYCEV-NET
inet6num: 2a03,c980,4,,/48 netname: ZAYCEV-NET descr: Zaycev.Net country: RU admin-c: ZR512-RIPE tech-c: ZR512-RIPE mnt-routes: DN-MNT status: ASSIGNED mnt-by: IHC-MNT created: 2016-08-12T06,54,47Z last-modified: 2016-08-12T06,54,47Z source: RIPE role: ZAO RMS address: ZAO RMS address: Novosibirsk, Dobrolyubova str., 10/1 address: 630009 Russia phone: +7 (495) 2118511 e-mail: email@example.com nic-hdl: ZR512-RIPE mnt-by: IHC-MNT abuse-mailbox: firstname.lastname@example.org created: 2015-11-19T08,39,30Z last-modified: 2015-11-19T08,39,30Z source: RIPE route6: 2a03,c980,4,,/48 origin: AS12695 mnt-by: DN-MNT created: 2016-08-12T11,39,04Z last-modified: 2016-08-12T11,39,04Z source: RIPE
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.