What is Custom Rom?

ROMS
Before going to install custom rom, What are the disadvantages of installing a Custom ROM?
1. Installing custom ROMs generally involves having to perform a clean wipe. So make sure you perform a backup of all your stuff!.
2. Custom ROMs may have bugs that cause your device to have issues
3. Voids the Manufacturer Warranty (just like rooting) Recovery and ROM, lets see some basic facts about them....
You may have heard of people loading custom “ROMs” on their Android devices. A “ROM” is the operating system software that runs your Droid. It is stored in the “Read Only Memory” portion of the hardware on the Android smartphone and/or tablet. All Android devices come with a stock ROM installed by the manufacturer. But, if you root your device, you gain the ability to install custom ROMs that will completely change the look and feel of the software. This is one of the major reasons that people choose to root their Droid
What Are Custom ROMS...???
Who makes them...???
Well, the Android platform is open-source which allows developers to take stock ROMs and modify them to make their own unique versions. Developers of custom ROMs are able to strip out all the garbage that manufacturers throw in, optimize the software, unlock some of the built-in features, and make an even better version of the Android software. The Android developers who make these custom ROMs then release the software to the general public to install on their rooted devices. The Android community is very lucky to have such a dedicated and hard working group of developers that are constantly working on making these custom ROMs available to enhance the Android experience for all of us.