Your IP address is like your postal address in the digital world, pinpointing where you live or work — or at least where your computer resides. It’s how other devices, computers, servers, and websites find each other and communicate.
Most networks that handle Internet traffic are packet-switched, with each piece of information sent in discrete chunks called packets. Each packet includes a header with a message and an ID, which helps route data to the right place. The header also includes the source and destination IP addresses. When routers receive a packet with a matching IP address, it is delivered to the appropriate device on the network.
Almost everything you do online leaves your IP address behind in server logs and the guestbooks of sites you visit, chatrooms you frequent, or blog comments you make. That means that if you’re not careful, cybercriminals 192.168.l.0.1 can use your IP address to connect those actions to you and your personal or business identity.
Every computer, server, printer, tablet, smartphone, or other device that connects to the Internet has a unique IP address assigned to it by its local network administrator. These addresses are the keys to your online presence, and without them you can’t get anywhere on the web.
While many of us are familiar with the term “IP address,” we may not understand how it works or why it’s important. We’re here to help.
The Internet’s backbone technologies are based on the TCP/IP Protocol, which manages how applications communicate across the network. The TCP/IP protocol identifies how applications send and receive messages by assigning each connected device its own IP address, which in turn is used to identify that device in a broader network.
IP addresses can be static (which indicates permanency) or dynamic, which allows them to change with the use of DHCP (Dynamic Host Configuration Protocol). Static IP addresses are used inside a network while dynamic IP addresses are used outside of the network, and both types of IP addresses can be public or private.
The international organization that oversees the global management of the Internet, ICANN, allocates blocks of IP addresses to regional Internet registries, which then assign smaller blocks to national registries and so on. Each Internet service provider (ISP), including mobile phone providers, then assigns individual client devices to those IP addresses. As of 2015, we were close to running out of IPv4 addresses. Fortunately, the Internet Engineering Task Force came up with the next version of IP, IPv6, which has a pool of 340 undecillion addresses, so we won’t run out anytime soon.