1st definition: Using computers and technology (analysis and exposure) to find new questions and answers in the humanities.
2nd definition: Digital Humanities is whatever someone who considers themselves to be a Digital Humanist happens to be doing.
Bit of a tautology. I came across this field after a few small projects of my own, and found that everyone who was doing work I found interesting and similar to my own was calling it Digital Humanities. In that sense I would say that DH is about methods and practice, rather than theory. I don’t even know that I would call it its own ‘field’. Instead it looks more like established fields of research learning new tricks.