Depending on which IRA you choose, the interest you earn may be tax deferred or tax free and the contributions you make may even be tax deductible. Consult your tax advisor. In exchange for a fixed-term commitment of your funds, you get high interest rates that are guaranteed for the entire period.
Terms range from six months to five years.
Many find this easier than making one large deposit each year. It's an especially good way to systematically save for retirement or a child's education.