(posterior view)
The muscles located in the posterior compartment of the thigh are known as "Hamstrings" and all of them act to extend at the hip and flex at the knee.
(frontal view)
Quadriceps Femoris is a group of muscles covering the front and side of the thigh. It includes the Rectus Femoris (bi-articular muscle), the Vastus Medialis, Lateralis and Intermedius (located deeper than the others).
(frontal view)
The muscles belonging to this Category (ours is simply a "topographical" categorization) are not all clearly visible in the summary image, as they are located at different depths.