inet6num: 2001:df1:6000::/48 netname: INFINEON-SG descr: 8 Kallang Sector country: SG admin-c: ITAP1-AP tech-c: ITAP1-AP mnt-routes: MAINT-INFINEON-SG mnt-routes: MAINT-SG-INFINEON mnt-irt: IRT-INFINEON-SG mnt-by: APNIC-HM status: ASSIGNED PORTABLE last-modified: 2013-05-21T10:12:21Z source: APNIC
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.