"Acquires a target" Vs "Notices a target In range". What's the Difference?

I can't quite grasp what the difference is between the two specific unit events:

• "Acquires a target"
• "Notices a target In range"
  
  

Anyone know?

Acquire a target is the first random attack (when an unit attack himself an ennemy near it)
Notices a target In range are the next random attacks

so if a unit already acquired a target and then another unit comes near he also notices them too even though he already has his first target and is chasing/attacking them?

Just test it with a display text message.
That's how i know the difference.
but i was talking about the attacker not the target