This video shows the difference between a defined-benefit pension plan and a defined-contribution plan. The core difference between these two types of plans boils down to what the employer is promising: with a defined-benefit pension plan, the employer is promising the employee a series of annuity payments after the employee retires. With the defined-contribution pension plan (e.g., a 401(k) plan), the employer is promising to make contributions to the employee’s retirement account.