1.
If you look through a group of things, you examine each one so that you can find or choose the one that you want.
Peter starts looking through the mail as soon as the door shuts.
= go through
PHRASAL VERB : V P n
2.
If you look through something that has been written or printed, you read it.
He happened to be looking through the medical book ‘Gray’s Anatomy’ at the time.
PHRASAL VERB : V P n