If it helps Jersey, the ACL stands for Anterior Cruciate Ligament which means it’s in the front part of your knee. There are three others. The PCL or Posterior Cruciate Ligament, the MCL or Medial Collateral Ligament, and the LCL or Lateral Cruciate Ligament.
Basically the ACL is in the front, PCL is in the back, MCL in the interior, and LCL in the outside portion of your knee. You also have meniscus in your knee which is another word for cartiledge.
I hope that helps.