[Gintoki Ameto]

I've been programming for many years. And in all of the language I've ever used, when you process a text file, you can either use text mode or bin mode.
When I try bin mode and write some text into it, I found that no difference to be regconize. So, my question is: What is the difference between text mode and bin mode? Is bin mode even necessary?
Thankyou for reading.