Any workplace plan will be included under the IRS as a "qualified plan"--i.e. qualified workplace retirement plan. An IRA is a private or "individual" retirement "arrangement" that you make on your own with a bank or broker. Even though both a Roth 401k and a Roth IRA have the same basic idea -- contribute after tax and don't pay tax when you retire, there are some important differences.
Some of the basic differences are,
| Qualified plan | IRA |
| Only contribute via payroll deductions |
Contribute your own money |
| Higher contribution limits | Lower contribution limit, contributions may be disallowed based on your income |
| Can't withdraw until you separate from service with the employer (unless you have a hardship and your employer allows hardship withdrawals) | Can withdraw at any time (but may be subject to tax) |
| Some employers may allow you to borrow from your 401k balance, with repayment via mandatory payroll deduction | You can't borrow from an IRA |
| 10% penalty for early withdrawal before age 59-1/2, unless you separate from service with the sponsoring employer at age 55 or above | 10% penalty for early withdrawal before age 59-1/2 |
| Certain exceptions to the 10% penalty that are allowed for IRAs are not allowed for qualified plans, see https://www.irs.gov/retirement-plans/plan-participant-employee/retirement-topics-tax-on-early-distributions | Some exceptions to the 10% penalty for early withdrawal under age 59-1/2 are allowed |