inet6num: 2a03,5880,,/32 netname: EU-IPTRON-20110914 country: EE org: ORG-IO15-RIPE admin-c: Ia1996-RIPE tech-c: Ia1996-RIPE status: ALLOCATED-BY-RIR mnt-by: RIPE-NCC-HM-MNT mnt-lower: MNT-IPTRON mnt-routes: MNT-IPTRON notify: email@example.com mnt-domains: MNT-IPTRON created: 2011-09-14T13,17,02Z last-modified: 2016-04-14T08,38,45Z source: RIPE organisation: ORG-IO15-RIPE org-name: IPTRON.NET OU org-type: LIR address: Iva 12 address: 12618 address: Tallinn address: ESTONIA phone: +3726106010 fax-no: +3726106010 e-mail: firstname.lastname@example.org mnt-ref: RIPE-NCC-HM-MNT mnt-ref: MNT-IPTRON mnt-by: RIPE-NCC-HM-MNT admin-c: KO372-RIPE admin-c: TV862-RIPE admin-c: MV88-RIPE abuse-c: Ia1996-RIPE created: 2011-09-12T12,44,08Z last-modified: 2015-11-25T12,12,55Z source: RIPE role: IPTRON.NET administrator address: IPTRON.NET OU e-mail: email@example.com org: ORG-IO15-RIPE admin-c: TV862-RIPE tech-c: TV862-RIPE nic-hdl: Ia1996-RIPE notify: firstname.lastname@example.org abuse-mailbox: email@example.com mnt-by: MNT-IPTRON created: 2011-09-14T11,49,35Z last-modified: 2011-09-14T11,49,35Z source: RIPE route6: 2a03,5880,,/32 descr: IPTRON.NET origin: AS12757 notify: firstname.lastname@example.org mnt-lower: MNT-IPTRON mnt-by: MNT-IPTRON created: 2011-10-25T11,36,43Z last-modified: 2011-10-25T11,36,43Z 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.