inet6num: 2001,67c,23c0,,/48 netname: UNI-KLU descr: Universitaetsstrasse 65-67 descr: A-9020 Klagenfurt country: AT org: ORG-UA194-RIPE admin-c: PG7058-RIPE tech-c: PG7058-RIPE status: ASSIGNED PI mnt-by: RIPE-NCC-END-MNT mnt-by: ACONET-LIR-MNT mnt-routes: ACONET-LIR-MNT mnt-routes: AS1111-MNT mnt-domains: ACONET-LIR-MNT notify: firstname.lastname@example.org created: 2011-07-25T10,29,50Z last-modified: 2016-04-14T08,29,23Z source: RIPE sponsoring-org: ORG-AA1-RIPE organisation: ORG-UA194-RIPE org-name: Universitaet Klagenfurt org-type: OTHER address: Universitaet Klagenfurt address: Universitaetsstrasse 65-67 address: A-9020 Klagenfurt e-mail: email@example.com abuse-c: UKAR1-RIPE mnt-ref: ACONET-LIR-MNT mnt-by: ACONET-LIR-MNT created: 2011-07-25T09,00,53Z last-modified: 2014-08-08T12,09,59Z source: RIPE person: Peter Gruber address: Universitaet Klagenfurt address: Universitaetsstrasse 65-67 address: 9020 Klagenfurt address: Austria phone: +43 463 2700 9612 fax-no: +43 463 2700 9666 e-mail: firstname.lastname@example.org nic-hdl: PG7058-RIPE mnt-by: ACONET-LIR-MNT created: 2011-02-15T12,45,09Z last-modified: 2011-02-15T12,45,09Z source: RIPE route6: 2001,67c,23c0,,/48 descr: UNI-KLU origin: AS1111 mnt-by: AS1853-MNT mnt-by: AS1111-MNT created: 2013-08-14T10,25,09Z last-modified: 2013-08-14T10,25,09Z 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.