Present Perfect Continuous use
1. ACTIONS THAT STARTED IN THE PAST AND CONTINUE IN THE PRESENT
She has been waiting for you all day (= and she's still waiting now).
I've been working on this report since eight o'clock this morning (= and I still haven't finished it).
They have been travelling since last October (= and they're not home yet).
2, ACTIONS THAT HAVE JUST FINISHED, BUT WE ARE INTERESTED IN THE RESULTS
She has been cooking since last night (= and the food on the table looks delicious).
It's been raining (= and the streets are still wet).
Someone's been eating my chips (= half of them have gone).