You all may have seen models created with Sculptris, Mudbox, Zbrush or Blenders own Sculpt mode. These can be really beautiful and detailed models and 9 times out of 10 they are unusable for animating. So understanding the reasons for edge loops as by now you should. You will find this next YouTube tutorial by Jjannaway3D,really helpful in finding a way to get these models back to an animatable form. Retopology is by far the best process for doing this. Now all your creations will be able to be used in your animations.