Question :
May I know what is ODIN and ROM? There isn't any official firmware upgrade through Samsung Kies. And I don't know how to upgrade my phone. My current device is Samsung Galaxy Mini GT-S5570 with android version is 2.2.1 Froyo in it. Also, I'm from Malaysia (if that helps). Can u help me?

Reply :
ODIN is a leaked program for flashing (installing) official Samsung Firmwares (aka. ROMs) on Samsung Handsets. Different versions of Odin are available for different Samsung android smartphone and the choice of the version of Odin depends upon your device's model. As for Galaxy Mini/Pop you need to use Odin Multidownloader v4.38 which can be downloaded from http://yagyagaire.blogspot.com/p/downloads-for-galaxy-mini-gt-s5570.html along with other necessary files including roms and recoveries.

ROM on the other hand stands for Read Only Memory. But, here it doesn't intend to mean the type of memory. Instead, it is used as a synonym to Firmware which is a program stored in read only memory. Or, in more simpler terms ROM here means the system that is running in your handset. There are various ROMs including some from Samsung and other from different users/developers open source community out there. While roms from Samsung are called Official Firmwares, systems from other open source community are called Custom Roms as they are customized from the source code of the official firmwares taken as base.

To upgrade your device, you have to collect Odin, corresponding OPS file and latest firmware from sammobile.com or other leaked firmware distributors. And, once you have all the required files you put your device to download mode (Press Volume Down + Home + Power button while your device is turned off to get to download mode) and then connect it to your PC. After that you need to prepare Odin with the firmware file(s) and press Start button when everything is ready. Your device should be upgraded within few minutes ranging from 5-10 minutes. Note, that you will fail to flash firmware if you don't have proper Samsung drivers installed on your PC. Installing Samsung Kies installs the required drivers along with the software.

That was just an overview of how you flash the firmware on any Samsung device. For your case, (i.e. for Samsung Galaxy Mini GT-S5570 smartphone) you can follow the detailed instructions at this article. However, since you are from Malaysia you will need to replace the firmware (said in the article linked above) with the one that is released for your device from sammobile.com. For this you can check your PDA and baseband by dailing *#*#1234#*#* in your Phone keypad and then noting down the details. Then you can match the first seven digits from the code you obtain with the firmwares available at sammobile. Do let me know if you have any doubts at the comments below.