We are using flash files for do software or update mobile old firmware. Flash files required at those stage if your mobile is working so slow or completely break. If little bit fault occurred in your mobile firmware you can solve it with updating of firmware. If you will update your mobile old firmware your mobile will resolve its firmware errors and your mobile will work so well.
Nokia developers putting new firmware updates for every phone on its official servers so if your mobile can support for online updating you can update it from your phone if your phones firmware haven’t corrupted completely. Some times your phone is working so slow or completely break you will need to flash your phone with its latest flash files. If you haven’t an experience in flashing please don’t take this action manually because during flashing your mobile going to be dead if you will flash your phone with corrupted flash files.