Everything sniffle has said is correct. I'll elaborate on your original question. Unfortunately, another lengthy answer is required to fully explain how the printers use memory.

The ATMEGA2560 processor used in the MakerFarm printers contains three types of memory. We'll describe them as flash, Electrically Erasable Programmable Read Only Memory (EEPROM), and Random Access Memory (RAM).

When a printer is up and running, it is executing the firmware code stored in the flash memory, using the RAM as workspace for various parameters, calculation results, and other variables. Contents of the flash memory will stay the way it is until the flash memory is damaged or new firmware has been uploaded to it. Along with the executable firmware code, the flash memory also contains what is described as "factory defaults" for settings and parameters. Don't be confused by the label factory - it doesn't imply MakerFarm as the factory. Factory simply refers to the firmware build that was last uploaded to the printer. Being able to change settings and parameters in a firmware upload is one method of changing them.

The Marlin firmware starts off by initializing the variable RAM space. If EEPROM is disabled, it will fetch the factory default values from the firmware upload stored in flash memory. If EEPROM is enabled, the data saved by the printer user to EEPROM will be used instead. Regardless of the source, this iniitialization only occurs once as the firmware starts up. After that, the contents of the settings and parameters in the RAM space will continue to be used until the ATMEGA2560 is reset or otherwise restarted. During the time the printer is up and running, many settings and parameters can be changed through either the LCD smartpanel or through gcode commands sent to the printer through host software. When changed from either the LCD or gcode, the updated values will again continue to be used until the ATMEGA2560 is reset. Updating RAM with settings and parameters from the LCD or gcode a second method of changing them.

Processors like the ATMEGA2560 are developed as general purpose processors - they aren't tailor designed for the 3D printer market. EEPROM space is available in the generic processor design for products that have a need to store some number of user-settable parameters in a non-volatile way without the risk and hassle of revising the flash memory contents. For example, in a clock design EEPROM might be used to store the daylight savings time mode, preventing the need for the user to re-enter the desired state every time the clock is restarted. Applying the generic processor design to our 3D printers, Marlin provides the option to store the settings and parameters in the EEPROM space as well. On command from either the LCD or receipt of the M500 gcode instruction, Marlin firmware will take the current state of key settings and parameters in the variable RAM space and copy them into the EEPROM. With Arduino, this is the only way to update the EEPROM contents. Storing settings and parameters and settings in EEPROM is a third method of managing them.

Again, when EEPROM is enabled, the settings and parameters stored there will be used by the printer instead of the "factory defaults" loaded with the firmware build in flash memory. On command, however, again from the LCD or here on receipt of the M502 gcode instruction, the RAM workspace will be loaded with the factory default settings and parameters. As described earlier, these values will then be used until changed from the LCD or gcode, or the printer is reset/restarted. The printer will again fetch the settings and parameters from EEPROM during the reset/restart.

To "erase" the effect of the EEPROM settings, you can disable EEPROM. Marlin will no longer look to EEPROM for settings when it is disabled. The other option available is to send the printer an M502 gcode command followed by an M500 command. The M502 copies the factory default settings from flash to RAM, and M500 in turn copies them from RAM to EEPROM. Similar manipulation is also possible through the LCD.