NRE/NRO accounts are meant for non resident Indians ... I am assuming you are travelling out for studies ? as per RBI guide lines NRIs are not supposed to hold regular bank accounts, you need to convert them to NRE/NRO accounts.
I am not an expert, but I think NRE accounts are not taxed ( it's used for stuff like sending money from your foreign account to India. And you would have anyway paid tax in the foreign country for that income, so you don't want Indian Govt. to tax it again. ). NRO accounts on the other hand is used for managing your "indian income" to say so (lets say you sold some property and got some profit, which you need to put it in the bank, it goes to your NRO account ... and that income is taxed ).
This is not something you should be pulling your hairs about. In fact its highly recommended to open NRE/NRO accounts if you are travelling out for long. Your banker should be able to give you more details on this. Feel free to bombard them with questions, they are there to win your money, they will be more than happy to help you. You would even start noticing that once you get an "NRI" label, you get "special treatment" from everyone in the bank.
Your existing savings can easily be transferred to your NRE/NRO accounts by the bank.
