According to Wikipedia, a traditional lunge “can refer to any position of the human body where one leg is positioned forward with knee bent and foot flat on the ground while the other leg is positioned behind.
It is used by athletes in cross-training for sports, by weight-trainers as a fitness exercise, and by yogis as part of an asana regimen.
Lunges are a good exercise for strengthening, sculpting and building several muscles/muscle groups, including the quadriceps (or thighs), the gluteus maximus (or buttocks) as well as the hamstrings.”
Good luck!