An Indian bank account for non-residents holding foreign earnings, freely repatriable and tax-free in India.
An NRE account lets Indians living abroad park foreign income in India in rupees. The principal and interest are freely repatriable back to the foreign country, and the interest is tax-free in India. Note that for U.S. tax residents, that interest is still taxable in the U.S. and the account counts toward FBAR and FATCA reporting.
An NRI deposits U.S. salary into an NRE account, earning India interest that is tax-free in India but taxable in the U.S.