Large Counts condition
The Large Counts condition checks that np is at least 10 and n(1-p) is at least 10, so the sampling distribution of p-hat is close to normal.
Large Counts is a sample size check: you need roughly 10 successes and 10 failures before you can treat the sampling distribution of (p-hat, the sample proportion) as normal; that is the textbook name for it, and the AP course framework calls the same check the normality condition. Which value of goes into the check depends on the procedure. A significance test has a hypothesized value, so you verify and using (p-naught); a confidence interval has no hypothesized value, so you verify and , which is just counting the observed successes and failures. Testing with passes, since and .
Where this comes up
More sampling distributions terms, or browse the full statistics glossary.