Human: I need to find out more about the benefits of a 401k. Assistant: 
A 401k is a retirement savings plan offered by employers that allows workers to save for retirement on a tax-deferred basis. It typically offers a variety of investment options and can help workers build a nest egg for their future. Contributions are made pre-tax, meaning they reduce taxable income before taxes are calculated. Additionally, withdrawals from a 401k are generally taxed at a lower rate than other types of retirement accounts.