The lateral lunge is a exercise to target the glutes and hamstrings. Although both feet are planted, it's more of a single leg exercise.

In the lateral lunge, you drive your hips back and put your bodyweight onto one leg. From there, I imagine pushing the ground away with the same leg im loading and thrusting the hips forward. The side you load, is the side of the glute you’re going to feel. You should feel a stretch on your other leg from keeping it straight as you lean.