Here our U.S. finance correspondent discusses tax-deferred growth:

Some investments give you the ability to enjoy tax-deferred growth. A traditional IRA, traditional 401k, 403b, and permanent life insurance all offer this ability. Plenty of other vehicles do as well. What exactly does it mean to have tax-deferred growth? It means that you “defer” (or put off) paying taxes on the gains and income in that account.

Let’s take an example. Suppose that you have $100 in an account. For easy math, let’s say you earn 10% on it during the year. That means you’ll have $110 in your account at the end of the year. If the 10% came as interest or dividends, do you have to pay taxes on it, and how much? The answer: it depends.

In a tax-deferred account, you will not pay taxes on your earnings this year. You can keep the extra $10 in there to continue to grow. Then, you get growth on top of your growth (otherwise known as compounding). Next year, you’ll have a whole $110 in the account that you can earn on.

However, assume that your account was not a tax deferred account. The IRS would say that you owe income taxes on $10 of income. Perhaps you have a hypothetical average tax rate of 25%. In that case, you’d owe $2.50 in taxes by next April! Where does the $2.50 come from? It’s up to you. You could pull it out of the account and leave $107.50 in there for future investment, or you could come up with the $2.50 from somewhere else.

Tax-deferred accounts help you compound money inside the account. There are always tradeoffs. For example, you might have to pay income tax when you take the money back out. Or, you might have to follow certain rules with the money – like leaving it in the account until you reach a certain age.