This is a very important thing to be done before you try flashing a firmware or recovery file.
USB Debugging mode makes Android devices receptive to download and send data over USB cable connection.
Odin is used to flash firmwares, kernels, ROMs and other files which are in the format.
The tool is a Standalone executable package which doesn’t need any special extensions, it’s quite simple in the design itself.
If you do not know how to turn debugging mode ON, do this: Most probably, you might already have Samsung USB drivers or Samsung Kies installed on your computer.
But if you have not yet installed any of them, it’s high time to do it now.
Make sure whether you’re flashing a compatible firmware or not before starting the process.In case you have installed Samsung Kies, make sure the program is closed while you use Odin or flash the firmware or it might interfere with the procedure.