inet6num: 2a00,f940,,/48 netname: REGRU-NETWORK descr: Reg.Ru country: RU admin-c: ARP-RIPE tech-c: RGRU-RIPE status: ASSIGNED mnt-by: REGRU-MNT mnt-routes: DN-MNT created: 2012-05-13T07,38,22Z last-modified: 2012-05-13T07,38,22Z source: RIPE role: Reg.Ru Network Operations address: Russia, Moscow, Vassily Petushkova st., house 3, Office 326 remarks: NOC e-mail, firstname.lastname@example.org remarks: User support, email@example.com remarks: SPAM reports, firstname.lastname@example.org phone: +7 (495) 580-11-11 fax-no: +7 (495) 491-55-53 e-mail: email@example.com admin-c: ARP-RIPE tech-c: ARP-RIPE tech-c: AH9460-RIPE nic-hdl: RGRU-RIPE mnt-by: REGRU-MNT abuse-mailbox: firstname.lastname@example.org created: 2011-03-30T12,49,27Z last-modified: 2014-12-23T12,18,22Z source: RIPE person: Pavel Arbuzov address: house 3, Vassily Petushkov str., Moscow, Russia, 125476 phone: +74955140573 e-mail: email@example.com nic-hdl: ARP-RIPE mnt-by: REGRU-MNT created: 2011-02-24T13,00,30Z last-modified: 2011-02-24T13,00,30Z source: RIPE route6: 2a00,f940,,/48 descr: Reg.ru origin: AS12695 mnt-by: DN-MNT created: 2012-05-14T07,16,46Z last-modified: 2012-05-14T07,16,46Z 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.