2620:30:4000::/48 - V6-01
AS1226 California Technology Agency
V6NetHandle: NET6-2620-30-4000-1 OrgID: CTA-42 Parent: NET6-2620-1 NetName: V6-01 NetRange: 2620:30:4000:: - 2620:30:4000:FFFF:FFFF:FFFF:FFFF:FFFF NetType: assignment OriginAS: 1226 Comment: http://www.otech.ca.gov RegDate: 2013-06-12 Updated: 2013-06-12 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.