inet6num: 2001,628,453,,/48 netname: AT-TLD-Technik descr: LAN AT Domain Technik country: AT admin-c: GW13-RIPE tech-c: GW13-RIPE mnt-by: ACONET-LIR-MNT status: ASSIGNED created: 2004-08-06T09,05,47Z last-modified: 2004-08-06T09,05,47Z source: RIPE person: Gerhard Winkler address: Vienna University address: Computer Center - ACOnet address: Universitaetsstrasse 7 address: A-1010 Vienna address: Austria phone: +43 1 4277 140 35 fax-no: +43 1 4277 9140 e-mail: firstname.lastname@example.org nic-hdl: GW13-RIPE remarks: NEW phone/fax number from 24-AUG-1997 mnt-by: AT-DOM-MNT created: 1970-01-01T00,00,00Z last-modified: 2001-09-21T23,23,10Z source: RIPE route6: 2001,628,453,,/48 descr: ACONET-VIX-SERVICES origin: AS1120 mnt-by: AS1120-MNT created: 2007-09-25T12,35,36Z last-modified: 2007-09-25T12,35,36Z 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.