A profit-sharing plan is a type of qualified defined contribution plan in which you, the employer, contribute to the accounts of participating employees. As the name implies, your employer contributions are generally (but not necessarily) tied to your business's profits, allowing employees to "share" in those profits. Annual contributions to the plan may be discretionary (you need not contribute anything at all), or may be based on a specific formula relating to your annual profits.
If you'd like a retirement plan that guarantees a specified benefit level at retirement regardless of investment results, you may want to consider a defined benefit pension plan. A defined benefit plan is a qualified employer-sponsored retirement plan that is funded solely by the employer (in most cases); it's the traditional type of pension plan. A defined benefit pension plan allows the highest potential contribution amount of any plan. These contributions are excluded from income and grow tax deferred. In addition, contributions can be deducted from business income.