This is a very difficult concept to explain. to track something means that your goal is to find a specific object/person, and you are looking for them by following clues/evidence etc. ex: my friend Bob stole my cookies and is hiding from me. I am going to track him down by following the crumbs. (I know that Bob did it, I am specifically looking for Bob) to trace something means that you have an end result, and are trying to find the cause, although you might not know exactly what the cause is. ex: someone stole my cookies (I'm not sure who). there is a trail of crumbs leading to my friend Bob's room, and he has crumbs on his hands. the evidence can be traced back to Bob, therefore Bob must have stolen my cookies. (I don't know who did it, so I am looking for information to figure out who did it)

To trace: follow the completed path backwards from its current point to where it began. To track: follow the emerging path forwards from your starting point to wherever the thing currently is.

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