They aren't the same. "Pension" means defined-benefit pension. You work here for 25 years and you'll get x thousand a month in retirement. It's how retirement

They aren't the same. "Pension" means defined-benefit pension. You work here for 25 years and you'll get x thousand a month in retirement. It's how retirement plans worked up until 1983 or so. 401(k) means market-based investing. You put y percentage of your paycheck aside, and the company may contribute some money, and it goes into Wall Street tax-deferred to hopefully gain value.