inet6num: 2a04,f310,,/31 netname: CZ-CZECHITC-20150930 country: CZ org: ORG-CICD2-RIPE admin-c: IKV9-RIPE tech-c: TV3003-RIPE tech-c: MD22356-RIPE status: ALLOCATED-BY-RIR mnt-by: RIPE-NCC-HM-MNT mnt-by: cz-czechitc-1-mnt mnt-lower: cz-czechitc-1-mnt mnt-routes: cz-czechitc-1-mnt created: 2015-09-30T09,12,28Z last-modified: 2016-08-22T10,37,47Z source: RIPE organisation: ORG-CICD2-RIPE org-name: CZECH IT CLUSTER, druzstvo org-type: LIR address: Benesova 1256/13 address: 586 01 address: Jihlava address: CZECH REPUBLIC phone: +420-731-635-458 e-mail: email@example.com admin-c: IKV9-RIPE tech-c: IKV9-RIPE abuse-c: AR33530-RIPE mnt-ref: RIPE-NCC-HM-MNT mnt-ref: cz-czechitc-1-mnt mnt-by: RIPE-NCC-HM-MNT mnt-by: cz-czechitc-1-mnt created: 2015-09-17T07,38,27Z last-modified: 2016-08-22T09,27,52Z source: RIPE person: Ing. Karel Vavra address: Benesova 1256/13 address: 586 01 address: Jihlava address: CZECH REPUBLIC phone: +420-731-682-720 nic-hdl: IKV9-RIPE mnt-by: cz-czechitc-1-mnt created: 2015-09-17T07,38,25Z last-modified: 2015-09-17T07,38,26Z source: RIPE person: Monika Dokoupilova address: Czech Republic phone: +420-222-742-740 nic-hdl: MD22356-RIPE mnt-by: MNT-DOKOUMO created: 2015-08-18T10,55,22Z last-modified: 2015-08-18T11,08,33Z source: RIPE person: Tomas Vondra address: Benesova 1256/13, 586 01 Jihlava, CZECH REPUBLIC phone: +420-731-635-458 nic-hdl: TV3003-RIPE mnt-by: cz-czechitc-1-mnt created: 2016-08-22T10,36,05Z last-modified: 2016-08-22T10,36,05Z source: RIPE route6: 2a04,f310,,/31 descr: IPv6 prefix of CZECHITC origin: AS12344 mnt-by: cz-czechitc-1-mnt created: 2015-10-07T10,19,14Z last-modified: 2015-10-07T10,19,14Z 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.