An IP address, or Internet Protocol address, is the address assigned to every device connected to a network, such as computers, web servers or printers. A device can have one IP address or several. Likewise, a single IP can be shared by many devices on the same network. Even so, it’s worth stressing that each IP is assigned only once.
What is an IP address used for?
An IP address is essential for transmitting data correctly from a sender to a recipient. It identifies and locates a device on an internal or external network, and that is exactly what happens during a transmission between two parties. When data is sent, the router checks the IP of the sender against that of the recipient. If they match, the transmission succeeds; if not, it fails.
IP addresses: versions and formats
There are two versions of IP addresses: IPv4 and IPv6. Let’s look at their characteristics.
IPv4 addresses
IP addresses of this kind are made up of 32 bits and are expressed as a 32-digit binary number. The sequence is usually written as 4 decimal numbers from 0 to 255 separated by dots. This format allows for a total of about 4.3 billion different addresses.
IPv6 addresses
An IPv6 address is a clear improvement over IPv4, offering a better and much larger address space than its predecessor. It was needed because the steady growth in internet-connected devices has been rapidly exhausting the IPv4 address space (covered in the previous section). That’s why this new format was introduced, with a number of possible addresses that runs to 37 zeros. An IPv6 address is made up of 128 bits, which would have to be written as a 128-digit binary number. Since that is far too long, hexadecimal notation is used instead, splitting the address into eight 16-bit blocks separated by colons.