If you're going to have a discussion about federal spending, it's important that you understand the difference between discretionary and non-discretionary spend

If you're going to have a discussion about federal spending, it's important that you understand the difference between discretionary and non-discretionary spending and why both are relevant. As well as understand what spending expenses have revenue (ie taxes) tied to them and which ones don't. I'm not going to be proscriptive here and argue for either. But simply leave it at make sure you understand the key factors / attributes of income and spending beyond just a pie chart.