Respuesta :
Because you put money from your paycheck into a 401k on a pre-tax basis, making contributions reduces your annual taxable income and the amount of tax you have to pay. ... This is similar to the way taxes work with a Roth IRA; however, a Roth 401k has a major advantage, because there's no income limit.
Advantages:
Your money goes in before taxes.
The company will often match your contribution.
You have many choices to allocate your money.
Disadvantages:
Your money is not available to be used before age 59.5 except under rare circumstances.
The money you put into this plan is not available for rent or car expenses.