To revert to Stock Firmware
This is the very basic thing you need to learn. This will help us keep our section tidy -no uber noob question that shouldn't be asked in the first place if you read this thread.
To revive/unbrick a dead phone
there would be times that as a beginner, you will be too trigger happy to try new tweaks and mods that in the end, you have nothing but a black shiny piece of square thingy and say that again, **** happens... and when that happens, you can either cry and pray that your phone will turn on or flood the forum asking for help simply because of being careless and being ignorant not to learn the basics and have a fall back plan. Odin Communicator's main function is not only to flash firmware files, but to revive your phone as well.
What is a firmware file?
Firmware file contains everything in your phone in software aspect. Samsung Galaxy Young's firmware contains 3 packages.
This is the ROM file. It contains apps, default wallpapers and sounds and of course the apps we hate the most -carrier specific bloatwares. Darn!
This is the MODEM file. This controls all the network radio on your phone, and anything network related. To cut it short, this is the BASEBAND of your phone.
This is the Country Sales Code file. It contains carrier related files, like carrier specific wallpapers and sounds and bloatwares that we hate the most. CSC is also responsible for the update you get from Kies.
To flash firmware files in Odin, you should have the 3 packages or else you will not be able to flash your phone correctly. The version of Odin (attached link) in this Guide accepts 1-file flashing, meaning you can flash PDA, PHONE or CSC without the need of having 3 of them. But again, it is better that you have 3 files to flash. Firmware flashing is no mix-and-match.
What's the difference between a Stock ROM and a Custom ROM?
These ROMS are ROMS that came with your phone, distributed by Samsung via Kies Update. It comes in different versions and may or may not be available depending on your region.
These ROMS are developed from stock ROMS. These ROMS contains mods and tweaks that enhances your phone. Though these ROMS have new fucntionalities, some ROMS aren't stable and often, custom ROMS for SGY are tested by users here on XDA as most developers don't have a Samsung Galaxy Young Phone and they rely on user feedbacks. Custom ROMS are categorized in two types:
made from stock ROMS. contains features like stock ROMS + new tweaks and improved performance.
Ports or Ported ROMS
Ported community created ROMS made entirely from an opensource android OS contains features from stock android OS + advanced features developed by community most popular ROMS are MIUI, CyanogenMod and some Chinese built ROMS which I don't remember the names