What's the Eisenhower Matrix?

Ferriss: I'm a left brain thinker. And so I think of things very logically, like I like to take messy things and put order around them. So I've always liked matrices and I gravitated towards matrixes - the Eisenhower matrix. The thing that came in was copywriting and copywriting. That was probably one of my biggest unlocks as an entrepreneur, is to really understand it.