inet6num: 2a04,9fc0,,/29 netname: NL-DIENST-ICT-20150331 country: NL org: ORG-GA233-RIPE admin-c: GA5500-RIPE tech-c: GA5500-RIPE status: ALLOCATED-BY-RIR mnt-by: RIPE-NCC-HM-MNT mnt-by: MNT-GAM mnt-routes: MNT-KPN-CUS created: 2015-03-31T13,06,13Z last-modified: 2017-05-18T14,21,39Z source: RIPE organisation: ORG-GA233-RIPE org-name: Gemeente Amsterdam org-type: LIR address: Postbus 94652 address: 1090 GR address: Amsterdam address: NETHERLANDS phone: +31202516000 fax-no: +31202516001 e-mail: firstname.lastname@example.org abuse-c: AR16163-RIPE mnt-ref: MNT-GAM mnt-ref: RIPE-NCC-HM-MNT mnt-by: RIPE-NCC-HM-MNT mnt-by: MNT-GAM created: 2010-06-16T11,42,22Z last-modified: 2017-05-18T14,21,40Z source: RIPE person: Gemeente Amsterdam address: Postbus 94652, 1090 GR Amsterdam NETHERLANDS mnt-by: MNT-GAM phone: +31202516000 nic-hdl: GA5500-RIPE created: 2010-09-16T12,37,10Z last-modified: 2015-05-18T10,56,39Z source: RIPE route6: 2a04,9fc0,,/29 descr: Gemeente Amsterdam origin: AS1136 notify: email@example.com mnt-by: MNT-KPN-CUS created: 2015-05-01T13,23,43Z last-modified: 2015-05-01T13,23,43Z 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.