If you are a US Citizen and you want to travel to India, what will you need? Of course you will need to book the hotels as well as the air tickets, and more importantly you will need to remember to bring your passport to the airport or not you cannot leave the boarder. However, apart from that, you will need a visa. If you are a US citizen having origins from India, then there maybe a special Indian visa for US Citizens of Indian Origin.
But first we will need to know what a visa is and why you need a visa to travel to Indian. First of all you will need to know that you are not a citizen of India, and that by default you cannot travel to India just by yourself-they will treat you as a trespasser and will have you arrested. This is not a good thing. After all, land are still exclusive asset of the State and unless by war or other diplomatic channels, you just cannot get the land from another country.
So, a visa is a permission for you to travel to that country. For example, if you are a USA citizen and you want to travel to India, then you will need to permission of the Indian government to let you stay inside their country for a prescribed period of time. This will usually have related to the purpose of your travel there, and you will need to really think about that. No matter what, you now know that if you travel to India without a visa, then you will be illegal to do that.
However, there are something special about Indian visa for US Citizens of Indian Origin, and that is called the OCI card. This is actually a solution for the demand of dual citizenship in India. If a citizen in the country want to immigrate to USA, and he does not want to totally give up their status as a person originally from India, then he will apply for a OCI card, and this is what this card is about. While the holder of this card is not totally recognized as a citizen in India, and therefore they do not have the right to vote as well as the right to purchase land in the country, it will be easier for them to travel back to India.
The key point about that is that the holder of the OCI card does not need a visa in order for them to travel to India-the OCI card is itself the visa and the card is the permission from the Indian government for them to travel back home at anytime they want for any period of time. Therefore, it will be much more convenient for those people to travel to India.
So, in short, if you are a USA citizen with a OCI card, then the visa thing is not of your worry at all.