2a01:c500::/28 - UNI2-NET
inet6num: 2a01,c500,,/28 netname: UNI2-NET descr: IPv6 Addressing for Orange Spain Network country: ES admin-c: HAF10-RIPE tech-c: HAF10-RIPE status: ALLOCATED-BY-LIR mnt-by: FT-BRX mnt-lower: UNI2-MNT mnt-routes: UNI2-MNT created: 2015-09-21T08,32,51Z last-modified: 2015-09-21T08,32,51Z source: RIPE role: Hostmaster Administrator FTE address: Parque Empresarial La Finca address: Edificio 9 address: Paseo del Club Deportivo, 1 address: 28223 Pozuelo de Alarcon address: Madrid, Spain e-mail: firstname.lastname@example.org admin-c: HA1066-RIPE admin-c: HA1067-RIPE tech-c: HA1066-RIPE tech-c: HA1067-RIPE nic-hdl: HAF10-RIPE remarks: spam, abuse reports....mailto,email@example.com abuse-mailbox: firstname.lastname@example.org mnt-by: UNI2-MNT created: 2005-08-19T10,24,55Z last-modified: 2013-01-17T16,47,17Z source: RIPE route6: 2a01,c000,,/19 descr: Orange S.A. origin: AS5511 mnt-by: FT-BRX created: 2013-10-08T12,49,32Z last-modified: 2013-10-08T12,49,32Z 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.