Tax-deferred is when you don’t have to pay taxes on a particular account as long as your money remains in it. You wait to pay the tax until you take the money. Once you withdraw your money, it’s up for grabs and the IRS can begin to tax it.
Retirement plans are a great example. Money stashed away in annuities, 401(k)s, and IRAs is tax-deferred to varying degrees and can grow for decades until you reach your retirement age.