401(k) Plan
A 401(k) plan is an employer-sponsored, tax-advantaged retirement savings plan. These plans fund with pre-tax employee- (and often matching employer-) contributions. Then, the accounts grow tax-free until withdrawal. 401(k) plans often provide employees with a choice of investment options--typically mutual funds.
403(b) Plan
A 403(b) plan is a tax-advantaged retirement savings program. It is available to employees of public education organizations, certain non-profits, and some self-employed ministers. Employees make pre-tax salary deferrals into the plan. These contributions grow tax-deferred until withdrawal.
457 Plan
The 457 Plan is a non-qualified, tax-advantaged, deferred-compensation retirement program. It is available for governmental and some tax-exempt non-governmental organizations. The employer sponsors the plan and the employee defers compensation into it on a pretax or after-tax (Roth) basis. This plan operates similarly to 401(k) and 403(b) plans. However, a key difference is that—unlike those plans—it has no 10% penalty for withdrawal before the age of 55. Still, the withdrawal remains subject to ordinary income taxation.