2001:4de0:1::/48 - NL-EWEKA-USENET-IPV6
inet6num: 2001,4de0,1,,/48 netname: NL-EWEKA-USENET-IPV6 descr: Eweka Internet Services USENET Backbone IPv6 country: NL admin-c: EISB1-RIPE tech-c: EISB1-RIPE status: ASSIGNED mnt-by: EWEKA-MNT created: 2008-04-09T11,37,01Z last-modified: 2008-04-09T11,37,01Z source: RIPE role: Eweka Internet Services BV address: Staten Bolwerk 1 address: 2011MK Haarlem address: The Netherlands phone: +31728500740 e-mail: email@example.com abuse-mailbox: firstname.lastname@example.org admin-c: PB6260-RIPE admin-c: PS12989-RIPE tech-c: PB6260-RIPE tech-c: PS12989-RIPE nic-hdl: EISB1-RIPE mnt-by: EWEKA-MNT created: 2003-05-13T22,56,30Z last-modified: 2015-05-21T09,01,19Z source: RIPE route6: 2001,4de0,1,,/48 descr: Eweka Internet Services USENET Backbone IPv6 origin: AS34343 mnt-by: EWEKA-MNT created: 2008-04-09T11,37,56Z last-modified: 2008-04-09T11,37,56Z 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.