Possible Duplicate:
Do you really use your reverse domain for package naming in java?
I am a beginner in android programming. I made a few android projects using eclipse.. while I was catching up with some android tutorials I could see everyone using "com" as a starting word of package name. I want to know why, as far as I have known it's just package name but why does everyone start with "com"? Do I have to follow? or is there any specific reason programmatically?