Facebook lite is an app developed for those users whose internet connection speed slow especially for 2G users. This app has its own messenger, you need not install messenger for texting.
I myself use this app when my network is slow.
You can do everything in this app which you do in the normal Facebook application.
You can watch videos, upload photos, chat with your friends, etc.
Finally I would say that this app would be best for the users whose internet connection is slow