Glossary

IP Address

An IP address is the unique numeric label assigned to each device on a network, used to route data to the right destination across the internet.

An IP address (Internet Protocol address) is the numeric label that identifies a device or service on a network and lets data find its way to it. Every server hosting a website has at least one IP address.

Two versions

ipv4 — 32-bit addresses written as 93.184.216.34. The pool is exhausted.
ipv6 — 128-bit addresses written as 2606:2800:220:1::1946. Vastly larger and increasingly common.

Public vs private

Public IPs are routable on the internet; private ranges (e.g. 192.168.x.x) are used inside local networks and hidden behind NAT.

Why it matters for hosting

DNS exists to translate domain names into IP addresses via a-record and aaaa-record entries. Knowing a site's IP lets you trace its asn, run a reverse-dns check, and identify the datacenter or cdn actually serving it. Shared hosting often places many sites on one IP, while a dedicated-server may have its own.

See also

IPv4 IPv4 is the original 32-bit internet addressing scheme, written as four dotted numbers, now exhausted and supplemented by IPv6. IPv6 IPv6 is the 128-bit internet addressing scheme that replaces scarce IPv4, offering a virtually unlimited supply of addresses. Reverse DNS (PTR) Reverse DNS resolves an IP address back to a hostname using a PTR record, commonly checked to verify mail servers and identify hosts. ASN (Autonomous System Number) An ASN is a unique number identifying a network of IP ranges under one operator, used by BGP to route traffic across the internet. DNS (Domain Name System) DNS is the internet phone book that translates human-readable domain names like example.com into the IP addresses computers use to connect.

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