A group of three muscles the gluteus maximus, gluteus medius and gluteus minimus.
The gluteals help us with all sorts of activities - like raising from sitting, walking and by moving our hip. Strong gluteals can help support the lower back offloading tight hamstrings.
But most of us do not use our bottoms! There are loads of exercises including mat-based and standing movements. Here is a free short mat-based glut work out for you all to try.
If you have any hip injuries, arthritis or bone density issues please drop me a message before giving these a go. There will be some modifications to make this a good exercise for you.