2001:df6:f600::/48 - IDNIC-ATWEB-ID
inet6num: 2001:df6:f600::/48 netname: IDNIC-ATWEB-ID descr: PT Mitra Persada Lentera Sejahtera descr: Corporate / Direct Member IDNIC descr: Jl. Agung Utara Blok A 36A No.16 RT. 014/08 descr: Sunter Agung, Tanjung Priok, Jakarta Utara admin-c: HM1078-AP tech-c: HM1078-AP remarks: send spam & abuse to: firstname.lastname@example.org country: ID mnt-by: MNT-APJII-ID mnt-irt: IRT-ATWEB-ID mnt-routes: MAINT-ID-ATWEB status: ASSIGNED PORTABLE last-modified: 2016-11-30T04:52:45Z 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.