IP address
The number that identifies a device on a network so packets can reach it.
An IP address identifies a network interface at the internet layer; routers forward packets by it, across as many networks as needed.
Examples
On the home network the greenhouse sensor is 192.168.1.37, the laptop is 192.168.1.10 and the router is 192.168.1.1.
An IPv4 address is 32 bits written as four numbers from 0 to 255, like 192.168.1.37.
See also