In the 80s computer companies were having new challenges sharing their software around the world. They often would use the words “internationalization” and “localization” to describe the process of translating the software. Developers are lazy and somewhere in the mid-late 80s they started abbreviating the words based on their first letter, last letter, and number of letters in between. This is why you’ll sometimes see i18n for internationalization and l10n for localization. There are also new numeronyms such as Andreessen Horowitz (a16z) and of course our favorite kubernetes (k8s).
Hopefully that will help give a little bit of background about the name.