I was flashing a **Samsung device** with a single file (`tar.md5` format) and i saw some people are working with 4 files(`Repairing firmware`) to fixing the most and actually, ***Any problems*** with those 4 files and i've heard that they says, it should fix any`(Software)` problems after flashing it on the device but *i couldn't actually* figured out ; 

**What is the exactly difference between these two** which the 4 files containts four files such as ;

* `Bootloader` file
* `CODE` file,
* `Modem` file
* and `CSC` file

And the single one has the `Modem` file and the others which we'd introduce it in `PDA` section?

Or, which one should be the best option for updating a device?

Also, i've seen an application which it could convert the `Single firmware` to four files and that was more interesting about the question too!