Mathematics
Discrete vs. Continuous Distributions
Quick fact
A continuous distribution assigns zero probability to any single exact value — only intervals have non-zero probability. That's why we use integration instead of summation.
Why this is interesting
If you roll a die, you can only get 1, 2, 3, 4, 5, or 6 — but when you measure someone's height, there are infinitely many possibilities. Why does that difference shape how we calculate probabilities?