V6NetHandle: NET6-2620-1FF-1 OrgID: IBRD Parent: NET6-2620-1 NetName: IBRD-V6-NET1 NetRange: 2620:1FF:: - 2620:1FF:FFF:FFFF:FFFF:FFFF:FFFF:FFFF NetType: assignment OriginAS: 10497 RegDate: 2014-05-22 Updated: 2014-05-22 Source: ARIN OrgID: IBRD OrgName: IBRD CanAllocate: Street: 1818 H Street, NW City: Washington State/Prov: DC Country: US PostalCode: 20433 RegDate: 2014-05-05 Updated: 2014-05-05 OrgAbuseHandle: ABUSE344-ARIN OrgAdminHandle: REVUT-ARIN OrgNOCHandle: NOC13298-ARIN OrgTechHandle: REVUT-ARIN OrgTechHandle: IP12-ARIN Source: ARIN
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.