A 401(k) is a type of retirement plan that allows employees to save and invest for their own retirement. Through a 401(k), you can authorize your employer to deduct a certain amount of money from your paycheck before taxes are calculated, and to invest it in the 401(k) plan. Your money is invested in investment options that you choose from the ones offered through your company's plan. The federal government established the 401(k) in 1981 with special tax advantages, to encourage people to prepare for retirement. They get their catchy name from the section of the Internal Revenue Code which established them.

You decide how much money you want deducted from your paycheck and invested during each pay period, up to the legal maximum (the IRS sets an annual dollar limit each year). You also decide how to invest that money, choosing from your plan's different investment options. The money you contribute to your 401(k) account is deducted from your pay before income taxes are taken out. This means that by contributing to a 401(k), you can actually lower the amount you pay each pay period in current taxes. For example, if you earn $1,000 each paycheck, and you contribute, say 5% ($50), you are only taxed on $950. You don't owe income taxes on the money until you withdraw it from the plan, when you could be in a lower tax bracket.