An IP address identifies a network interface within an addressing scope. A device may have several addresses, and private addresses can be reused across separate networks. Think of it like the address on an envelope — it's how data packets know where to go.
What's the difference between IPv4 and IPv6?
IPv4 addresses are 32 bits long, written as four segments like 192.168.1.1. The total address space is about 4.3 billion; scarcity of public allocations has encouraged extensive use of NAT. IPv6 is 128 bits long, written like 2001:0db8:85a3::8a2e:0370:7334, and offers a practically inexhaustible address space.
Public vs. private IP
- Public IP: The address your ISP assigns you that's visible on the internet.
- Private IP: An address used within a private network, assigned through DHCP or configured manually (e.g. 192.168.x.x).
When you connect to a website, your browser resolves the destination server's IP via DNS, then data packets travel back and forth over that address. Want to check your own? Try our IP lookup tool.
Why does your IP matter?
It can reveal your approximate location, ISP, and sometimes your organization — which is why privacy-conscious users increasingly rely on VPNs.
References
RFC 1918. Technical review: 11 October 2026.