inet6num: 2a01,5380,,/32 netname: EU-OPTINET-20110609 country: GB org: ORG-MCL27-RIPE admin-c: IC9888-RIPE tech-c: IC9888-RIPE status: ALLOCATED-BY-RIR mnt-by: RIPE-NCC-HM-MNT mnt-by: MWEB-CONNECT-MNT mnt-routes: MWEB-CONNECT-MNT notify: email@example.com created: 2011-06-09T09,56,52Z last-modified: 2017-05-03T12,40,28Z source: RIPE organisation: ORG-MCL27-RIPE org-name: Dimension Data (Pty) Ltd org-type: LIR address: Le Mans Building, The Campus, 57 Sloane Street, Bryanston address: 2021 address: Bryanston address: SOUTH AFRICA e-mail: firstname.lastname@example.org abuse-c: AR13627-RIPE mnt-ref: MWEB-CONNECT-MNT mnt-ref: RIPE-NCC-HM-MNT mnt-by: RIPE-NCC-HM-MNT mnt-by: MWEB-CONNECT-MNT created: 2011-06-07T14,38,30Z last-modified: 2017-05-03T12,40,30Z source: RIPE phone: +27215968840 fax-no: +27215968869 admin-c: IC9888-RIPE person: Ian Castleman address: 100 Fairway Close address: Parow address: Cape Town 7500 address: South Africa phone: +27215964728 e-mail: email@example.com nic-hdl: IC9888-RIPE mnt-by: MWEB-CONNECT-MNT mnt-by: IS-OPTINET-MNT created: 2011-01-19T16,30,35Z last-modified: 2015-06-30T09,02,22Z 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.