| Term | Description |
| IPv4 | IPv4 (Internet Protocol version 4) is still the most commonly used Internet Protocol (IP) version, initially deployed in 1983. IPv4 addresses are 32-bit numbers often expressed as 4 octets in "dotted decimal" notation (for example, 192.0.32.67). IPv6 is the newer version of the Internet Protocol (deployment began in 1999) that offers many improvements over IPv4, such as 128-bit IP addresses, and will eventualy completely replace IPv4. |