As the names suggest, mid rise and high waisted leggings really differ in terms of cut. Mid rise leggings rest across your natural waist, which tends to sit below your belly button. High rise leggings, on the other hand, have an extra width of fabric sewn into the top of the pants that brings the waistline above your hips.
Both have pros and cons — the style you choose should depend on the activities you are engaging in.