They are entirely unrelated.
Dark matter is an as yet unknown substance. We call it dark because it does not interact with the electromagnetic force, or light, and therefore is invisible. Dark matter does have mass, and does exert its gravitational force on regular matter. Years ago, physicists were looking for an explanation as to why spiral galaxies, which should fly apart as its arms swirl around the center, remain intact. Something with great mass surrounding the galaxies seems to hold the spiral arms in place, otherwise they would fling billions of stars into space. So dark matter emerged as the best theory. Contraversy remains as to whether this is actually a new kind of matter, or the effects of gravity at large scales.
Dark energy is believed to be the force of the expansion of the universe. This is vacuum energy, the force that tends to push objects away from each other. This force was confirmed in the famous Casimir expirement in 1948. Dark energy acts as an anti-gravity force, pushing the large galactic clusters further apart as it expands the size of the voids between them.