IP stands for Internet Protocol which is a hand-shaking language shared among internet devices. An IP address, which is often shortened as IP, is a unique 32-bit number to identify each device and communicate with each other on the internet. Any participating device -- including routers, computers, and servers -- must have its own unique address. This allows information datagram passed across an internet to know where it exactly heads to.

Conceptually, every internet device attached to an internet is assigned a 32-bit universal identifier as its internet address which ranges from 0.0.0.0 to 255.255.255.255. Technically, each address consists of two parts: network identifier and device identifier. The network portion is used to identify the specific network where the datagram is routed to; and the device portion is used to locate the specific device on that network.

The unique nature of IP addresses makes it possible in many situations to track which device -- and by extension, which person -- has sent a message or engaged in some other activity on the Internet. This information can be used for many purposes such as targeting intended visitors by commercial advertisers or identifying malicious activities like spamming or hacking by enforcement authorities.