Unhappy What is the diffrent between Dr.Ketan, Omini ROM and Ditto 5.2

Hello friend my question is about custom ROM??
What is the different between Dr.Ketan, Omini ROM and Ditto 5.2, really i am new user for mobile root and custom ROM so please clear me. I think OMINI is main OS like Microsoft windows and other one is software like MS office, Photo shop etc. am i right friend so please please please help me about it.