In the left of the two images here, we have popped in a little x-ray so that you can orientate yourself when you look at the other illustration to its right.
You can see the two menisci between the femur and the tibia bones. The wedge-shaped meniscus accommodates the incongruity between the rounded end of the femur and the flat surface of the tibia.
Each meniscus is curved like a pair of horns - the front bit is called the anterior horn, and the back bit is the posterior horn. The meniscus on the inner side is called the medial meniscus and the one on the outer side is the lateral meniscus.
On the left we have another illustration, also of the left knee, but showing the bones from the front. The femur bone looks a bit funny as the knee is bent so that you can see the menisci - and in the bent knee you are faced with the rounded cartilage ends of the femur bone and cannot see the shaft.
On the right is a photo taken close-up during arthroscopy.