inet6num: 2a02,d80,,/32 netname: SI-SGN-20090421 country: SI org: ORG-SD12-RIPE admin-c: MU520-RIPE tech-c: SGN-RIPE status: ALLOCATED-BY-RIR mnt-by: RIPE-NCC-HM-MNT mnt-by: MNT-SGN mnt-lower: NETSI-MNT mnt-lower: MNT-SGN mnt-routes: NETSI-MNT notify: firstname.lastname@example.org created: 2009-04-21T09,45,42Z last-modified: 2016-11-23T22,22,58Z source: RIPE organisation: ORG-SD12-RIPE org-name: SGN d.o.o. org-type: LIR address: Tivolska cesta 50 address: 1000 address: Ljubljana address: SLOVENIA phone: +386 1 430 2888 fax-no: +386 1 430 2889 e-mail: email@example.com admin-c: AD126-RIPE mnt-ref: MNT-SGN mnt-ref: RIPE-NCC-HM-MNT mnt-by: RIPE-NCC-HM-MNT mnt-by: MNT-SGN abuse-c: SGN-RIPE created: 2007-01-03T13,12,06Z last-modified: 2016-11-23T22,23,09Z source: RIPE role: SGN Hostmaster address: SGN d.o.o. Tivolska cesta 50 SI-1000 Ljubljana Slovenia abuse-mailbox: firstname.lastname@example.org e-mail: email@example.com admin-c: AD126-RIPE tech-c: AD126-RIPE nic-hdl: SGN-RIPE mnt-by: MNT-SGN created: 2007-01-05T17,48,10Z last-modified: 2009-10-10T18,55,57Z source: RIPE person: Mitja Uhan address: Metaling d.o.o. Krakovo 11 SI-1433 Radece Slovenia phone: +386 3 428 8500 fax-no: +386 3 490 4741 abuse-mailbox: firstname.lastname@example.org e-mail: email@example.com nic-hdl: MU520-RIPE notify: firstname.lastname@example.org mnt-by: NETSI-MNT created: 1970-01-01T00,00,00Z last-modified: 2009-10-10T19,05,35Z source: RIPE route6: 2a02,d80,,/32 descr: NETSI.NET origin: AS12778 mnt-by: NETSI-MNT created: 2009-04-22T01,13,07Z last-modified: 2009-04-22T01,13,07Z 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.