What Is an IP Address?
an IP Address — a numerical label assigned to every device on a network, used to identify it and route data to it — the internet's addressing system, in IPv4 (like 192.168.1.1) or IPv6 form.
How it works
Every device that communicates on a network needs a unique address so others know where to send replies. IP addresses are hierarchical (network portion + host portion, defined by a subnet mask) — this structure is what lets routers forward efficiently instead of needing to know every device individually.
Why it matters
The IP address is the single most fundamental concept in networking — everything (subnetting, routing, NAT, DHCP) exists to manage and assign IP addresses efficiently. Start with IP address classes and subnetting.
Frequently asked questions
What is an IP address used for?
Uniquely identifying a device on a network so data can be correctly routed to and from it.
What is the difference between a public and private IP address?
A public IP is globally unique and routable on the internet; a private IP is used within local networks and requires NAT to reach the internet.
What is the difference between IPv4 and IPv6 addresses?
IPv4 uses 32-bit addresses in decimal notation (192.168.1.1); IPv6 uses 128-bit addresses in hexadecimal (2001:db8::1), providing vastly more addresses.
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