A network address for Internet traffic
An IP address is a numeric identifier used by the Internet Protocol. When your browser contacts a website, packets need source and destination addresses so routers know where to send them and where replies should return.
The word address can be misleading: an IP is not a postal address and usually does not identify a person by itself. It identifies a network endpoint or a path to one. That endpoint may be a home router, a company gateway, a server, a mobile network or a shared carrier gateway.
192.0.2.42; an IPv6 address can look like 2001:db8::42. These example ranges are reserved for documentation.How IP is used
Internet data is split into packets. Routers inspect network information and forward those packets from one network to the next. DNS often comes first: it converts a name such as example.com into one or more IP addresses that the network can route to.
IP is only one part of the stack. Ports identify services, TCP or UDP define transport behavior, and application protocols such as HTTPS define how software communicates.
Public and private addresses
Home devices usually receive private addresses on the local network, while the Internet-facing connection uses a public address. NAT allows several devices to share one public IPv4 address. Some ISPs add another shared layer called CGNAT, which can place multiple customers behind the same public IPv4 address.
Dynamic and static IPs
A dynamic IP can change over time. A static IP is intended to stay stable and is useful for hosted services, access rules and some business setups. Static vs dynamic is separate from public vs private.
What can an IP reveal?
Public IP data can often identify an ISP, ASN and approximate geographic area. It does not normally reveal an exact street address. Use the IP geolocation tool or browser privacy audit to see the difference between network data and browser data.