That's true, but STOCKFREAK is right as well; they aren't daytraders. They're swing traders or some other brand of short term traders.
The number one rule of an actual daytrader is: "Never, ever hold a position overnight".
This doesn't mean you can't do both. Only one of my five strategies is a daytrading strategy, which means that I never hold positions that I buy under that strategy overnight. My other strategies have time frames of several days though, and I often hold THOSE positions overnight or even for weeks in some cases.