Human: What is the difference between a 401K, a 403B, and a 457? Assistant: 
A 401(k) is an employer-sponsored retirement savings plan. It allows employees to contribute pre-tax money from their paycheck into a retirement account. A 403(b) is also an employer-sponsored retirement savings plan, but it allows employees to make contributions that are not taxed until they withdraw them in retirement. Finally, a 457 is a type of tax-deferred annuity offered by some employers, which can be used for retirement planning.