A tax-deferred account allows you to postpone income tax that would otherwise be due on employment or investment earnings you hold in the account until some point the future, often when you retire.
For example, you can contribute pretax income to employer retirement plans, such as a traditional 401(k) or 403(b).
You owe no tax on any earnings in these plans, or in traditional individual retirement accounts (IRAs), fixed and variable annuities, and some insurance policies until you withdraw the money. Then tax is due on the amounts you take out, at the same rate you pay on your regular income.
A big advantage of tax deferral is that earnings may compound more quickly, since no money is being taken out of the account to pay taxes. But in return for postponing taxes, you agree to limited access to your money before you reach 59 1/2.