Livestream with Multiple Languages ????

I saw on the Wowza website this:

Communicate in Multiple Languages

Wowza Media Server 3’s multi-track audio channel selection capabilities simplifies streaming in multiple languages. You can easily choose languages from source streams with multiple audio tracks and deliver them simultaneously for users to select on computers, mobile devices and IPTV set-tops.

How this is works ? what is the configuration of stream to do that ?

And on the computer ? I need a multiple sources of audio ? can i do that with a single computer using FMLE ?

Take a look at this example:

https://www.wowza.com/docs/how-to-control-video-and-audio-pid-and-streamids-for-outgoing-mpeg-ts

Richard