IPv4 vs IPv6
You may have seen your IP address written two very different ways. That is IPv4 versus IPv6, the old and new versions of internet addressing. Here is the difference, simply.
IPv4: the classic format
IPv4 addresses look like 192.168.1.1, four numbers separated by dots. There are about 4.3 billion of them, which sounded like plenty in the 1980s but has since run out as billions of phones and devices came online.
IPv6: the newer, bigger format
IPv6 addresses are much longer, like 2001:0db8:85a3::8a2e:0370:7334, using numbers and letters. There are so many that the internet will never run out. IPv6 also has some built-in efficiency and security improvements.
Which one do you have?
Most people have both. Your network may use IPv6 where available and fall back to IPv4 elsewhere, which is why a lookup tool sometimes shows one or the other. Neither is "better" for everyday use; IPv6 simply solves the address shortage.
Check your address
Curious which one you are on right now? See how to find your IP to check, and what an IP address is for the basics.