Two words: tax advantaged.
What that means is that the money in your IRA grows free from the clutches of Uncle Sam. So unlike the money you have in a regular brokerage account, the income from interest, dividends and capital gains can compound each year without taxes nipping away at it.
In addition, you also can escape taxes on either the money you put into the plan initially or on the money you withdraw in retirement, depending upon whether you choose a traditional or Roth IRA.
So what's the downside? Only that you can’t stash more. The government limits the amount of money you can put into an IRA each year. Most people under 50 can contribute no more than $5,500 a year; that limit rises if you're older.