It's a capacitive touch screen - no digitizer. There's a 7579 model and on that one, there is an option for a pen-compatible digitizer. Those models will ship with a "pen compatible" sticker on them - not all of them are pen-compatible, even on the 7579.
How can you tell?
I have a 7570 and the screen properties says it supports "Pen and Touch with 10 Touch points".
I also got the Dell Pen for it which requires batteries. So I assumed it's active. I figured it was a hybrid digitizer/capacitive.
Here's a sample of me using the pen on it and writing on the screen and selecting a pen or pencil type point. It works really well, and shows off my poor hand writing really well. It's like writing on paper with a pen.
I also have an Asus T100A 2in1 tablet which has a standard capacitive screen, and does not support a pen other than the non powered smushy/mesh type and does not work anywhere as well as the 7570.