Human: What's the difference between a 401k and a IRA? Assistant: 
The primary difference between a 401k and an Individual Retirement Account (IRA) is their funding source. A 401k is funded with pre-tax contributions, meaning you can take advantage of tax deductions when contributing to your account. An IRA, on the other hand, allows for post-tax contributions and withdrawals without incurring taxes or penalties upon withdrawal. Additionally, 401ks typically have higher contribution limits than IRAs, allowing you to save more money over time.