Illustrator supports Unicode, a standard that assigns a unique number to every single character, no matter which language or type of computer you use. Unicode is:

Portable

Letters and numbers will not change when you move the file from one workstation to another. Adding a foreign language to a document doesn’t cause confusion, because foreign characters have their own designations that don’t interfere with the encoding from other languages in the same project.

Platform-neutral

Because Windows and Macintosh operating systems now support Unicode, moving a file between the two platforms is easier. No longer will you need to proofread an Illustrator file just because you moved to it a Windows computer from a Macintosh computer or vice versa.

Robust

Because Unicode‑compliant fonts offer a larger number of potential characters, specialty type characters are readily available.

Flexible

With Unicode support, substituting a typeface in a project won’t result in substituted characters. With a Unicode‑compliant font, a g is a g no matter which typeface is used.

All of these things make it possible for a French designer to design for a client in Korea and hand the job off to a partner in the United States without having to struggle with the text. All the U.S. designer needs to do is enable the correct language in the operating system, load the foreign‑language font, and continue the project.