inet6num: 2a04,440,,/29 netname: PL-UMCS-20130123 country: PL org: ORG-MCU1-RIPE admin-c: LUBM3-RIPE tech-c: LUBM3-RIPE status: ALLOCATED-BY-RIR mnt-by: RIPE-NCC-HM-MNT mnt-by: PL-LUBMAN-MNT mnt-routes: PL-LUBMAN-MNT notify: email@example.com created: 2013-01-23T11,55,33Z last-modified: 2016-12-12T08,41,50Z source: RIPE organisation: ORG-MCU1-RIPE org-name: Maria Curie-Sklodowska University org-type: LIR address: pl. Marii Curie-Sklodowskiej 5 address: 20-031 address: Lublin address: POLAND phone: +48815376192 fax-no: +48815376192 e-mail: firstname.lastname@example.org abuse-mailbox: email@example.com admin-c: GS12541-RIPE admin-c: AU229-RIPE admin-c: AR1187-RIPE admin-c: AD6207-RIPE tech-c: LUBM3-RIPE mnt-ref: PL-LUBMAN-MNT mnt-ref: RIPE-NCC-HM-MNT mnt-by: RIPE-NCC-HM-MNT mnt-by: PL-LUBMAN-MNT abuse-c: LUBM4-RIPE created: 2004-04-17T11,48,25Z last-modified: 2016-12-12T08,42,08Z source: RIPE role: LUBMAN UMCS Operators address: Uniwersytet M. Curie-Sklodowskiej address: LubMAN UMCS address: pl. M. Curie-Sklodowskiej 5 address: 20-031 Lublin address: Poland phone: +48 81 537 2000 fax-no: +48 81 637 2027 e-mail: firstname.lastname@example.org e-mail: email@example.com admin-c: AR1187-RIPE admin-c: AU229-RIPE tech-c: AR1187-RIPE tech-c: MJ20-RIPE tech-c: GS12541-RIPE nic-hdl: LUBM3-RIPE notify: firstname.lastname@example.org abuse-mailbox: email@example.com mnt-by: PL-LUBMAN-MNT created: 2007-10-11T10,43,54Z last-modified: 2012-03-22T12,00,37Z 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.