Profit-sharing plan vs. 401(k)
The key difference between a profit-sharing plan and a 401(k) plan is that only employers contribute to a profit-sharing plan. If employees can also make pre-tax, salary-deferred contributions, then the plan is a 401(k).
Employee contributions are always 100% vested in a 401(k), whereas business owners contributing to a profit-sharing plan can impose vesting requirements. That means you may forfeit these contributions if you don't fulfill certain minimum work requirements.
Employees get the best of both worlds when an employer offers a 401(k) while also offering a profit-sharing plan. However, workers don't get to choose what type of retirement plan employers provide.
If your company offers a profit-sharing plan but no 401(k), look into other tax-advantaged contribution plans, such as an individual retirement account (IRA), so you can invest for your future.