Official ROM and Custom ROM of Android Phones

Firmware: Files used for mobile phone reprogramming or flashing are called firmware, fashfile and Rom.

There are two types of firmware available on Android phones.

1.Stock Rom/Official firmware/Original firmware.

These are the files officially released by the manufacturing company for each device.

2.Custom Rom/ modified Rom.

CustomRom are files created by making changes (customization) in official firmwares.

Using custom firmware will void the warranty of the device.

Using custom firmware may cause problems like Hang on Logo, Restart, Baseband, IMEl ​​Missing etc. in some phones.

So, when using custom firmware on working phones, backup the phone's security files.

Circumstances Where Custom Firmware Needs To Be Used

1.No update in official rom.

Example: Samsung T560 Android Tablet is available only with Official Rom 4.4. In this version it is not possible to use apps like Youtube, zoom, map, whatsapp etc

Samsung T560 with 4.4.4 (official ROM)

Samsung T560 with 7.1.2 (custom ROM)

But custom firmware is availablefor this Tablet. It is available in Android 6, 7 and 8 versions.

2. For Model convert /Region Change/Language change.

Providers such as Docomo, T-mobile, Sprint... have different menu, settings, language etc. Custom firmware is used to convert it to normal settings.

Japan Docomo S7 edge 

After using Custom Firmware

Example: A Japan S7 Edge SC-02H (Figure 3) can be converted to a standard S7 Edge using a custom file (Figure 4).

[Not only for Samsung, Custom firmware is also available on all Android phones.]