ipWhat is an IP address and what does it do?
Understand how IP addresses support connections, what a visible address represents, and what a lookup can reveal.
Read guideIP basics
Practical guides to IP addresses, DNS, networking and privacy.
8 guidesHow to read an IPv4 address
Learn the four parts of an IPv4 address, valid number ranges, and the difference between an address and a port.
Read guideWhat is IPv6? A practical guide to its addresses
Understand IPv6 notation, double-colon compression, and why a device can use more than one IPv6 address.
Read guideIPv4 vs IPv6: the differences that matter
Compare IPv4 and IPv6 addressing, dual-stack connections, and the reasons lookup results may differ.
Read guidePublic vs private IP: what is the difference?
Learn why your router and an IP lookup site show different addresses, and how private and public addressing differ.
Read guideStatic vs dynamic IP: when does it matter?
Compare static and dynamic IP addressing, address changes, and practical considerations for remote access.
Read guideHow does IP geolocation work?
Understand IP location databases and why the point shown on a map is only approximate.
Read guideWhat are localhost and 127.0.0.1?
Learn about loopback addresses, local development, and why localhost refers to a different machine for each user.
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