WHY THIS MODULE?: Microcontroller’s flash memory is erased the moment you cutoff it’s power. To store something permanently we’ll need to write stuffs into EEPROM.This module is kind of like a pen drive for your Arduino/ microcontroller. If you pull the pen drive out of your computer, it will not get any power. But surely it’ll store your data. Same goes for this module. There are 0 to 32767 (in hex 0x0000 to 0x7FFF, first two are HIGH addresses and last ones are LOW addresses) addresses where you can store 8 bit data.