Jennifer, women's jeans are generally more full in the hips, on the sides, and lower in the waist (low rise), the zipper doesn't unzip as low as men's jeans do, and pockets are often less deep. Sometimes they are cut to fit higher in back than in front, to allow for a more generous rear end and to avoid pulling down when you sit or bend over.
Some will pass well in drab, and some have obviously girly decorations added.