inet6num: 2a05,c740,,/29 netname: SE-NMT-20150213 country: SE org: ORG-NMA5-RIPE admin-c: ULFV1-RIPE tech-c: ULFV1-RIPE status: ALLOCATED-BY-RIR mnt-by: RIPE-NCC-HM-MNT mnt-lower: SE-NMT-MNT mnt-routes: SE-NMT-MNT created: 2015-02-13T09,37,48Z last-modified: 2016-04-14T09,03,29Z source: RIPE organisation: ORG-NMA5-RIPE org-name: Netett Sverige AB org-type: LIR address: BOX 7460 address: SE 10392 address: Stockholm address: SWEDEN phone: +46704441066 fax-no: +4687555985 e-mail: email@example.com abuse-c: NAH24-RIPE admin-c: JT6374-RIPE admin-c: ULFV1-RIPE admin-c: MABR4-RIPE admin-c: MN10566-RIPE mnt-ref: SE-NMT-MNT mnt-ref: RIPE-NCC-HM-MNT mnt-by: RIPE-NCC-HM-MNT created: 2006-10-20T13,28,59Z last-modified: 2015-11-20T13,29,10Z source: RIPE person: Ulf Vedenbrant address: Regeringsgatan 25 address: Stockholm address: Sweden phone: +46733141913 nic-hdl: ULFV1-RIPE mnt-by: SE-NMT-MNT created: 2006-11-08T20,15,51Z last-modified: 2011-03-05T23,12,10Z 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.