/ˌaɪ-ˈpiː/
n. “Addresses in a digital world.”
IP, short for Internet Protocol, is the fundamental addressing system that allows devices to locate and communicate with each other across networks. Think of it as the digital equivalent of a postal address — without it, your messages, packets, and data would have nowhere to go. IP works hand-in-hand with TCP to form the foundation of the internet, commonly referred to as TCP/IP.
There are two major versions in use today: IPv4 and IPv6. IPv4 uses 32-bit addresses, allowing for roughly 4.3 billion unique addresses, which seemed infinite in the early days of the internet but quickly became scarce. IPv6 expands the address space to 128 bits, creating an astronomical number of unique addresses and future-proofing the network for generations of connected devices.
Each IP address identifies a network interface rather than a user or device directly. For example, your laptop, smartphone, and IoT devices all have IP addresses when connected to a network. Routers, switches, and gateways use IP to determine the most efficient path for data packets, a process known as routing.
IP handles the addressing and delivery part of the network communication. Unlike TCP, it does not guarantee delivery or order. That’s where transport protocols like TCP step in, ensuring reliability over the sometimes unreliable routes the internet provides. Without IP, even TCP would be lost — literally.
Practically, IP allows you to load a website, send an email, stream a video, or connect to a VPN like OpenVPN or WireGuard. Each of these activities relies on IP to correctly address the packets across potentially billions of routers and switches in the global network.
Network administrators, cybersecurity professionals, and developers often use IP addresses for monitoring, filtering, and configuring traffic. Tools like ping, traceroute, and packet sniffers are all built on the concept of IP, giving visibility into the otherwise invisible flow of digital information.
In short, IP is the backbone of digital communication. It names, locates, and helps route data to the right place, enabling all the applications, protocols, and services we rely on daily. Lose IP, and the internet as we know it simply ceases to function.