Difference between look, see and watch

To see is to perceive things with one’s eyes. Note that you can see things whether or not you are paying attention.
Suddenly I saw a dark figure behind the curtains. (NOT Suddenly I watched a dark figure behind the curtains.)
It was a sight to see.
Did you see the article about food poisoning in today’s paper?
Continuous forms of see are not normally used with this meaning.
I can see a camel. (NOT I am seeing a camel.)
Look at
To look at something is to try to see what is there. Note that you can’t look at something if you don’t want to.
I looked at her but I didn’t see any expression on her face.
He looked at her affectionately.
Look at him.
They were looking at some books.
When look has an object, it is followed by a preposition. If there is no object, we do not use any preposition.
Look! (NOT Look at!)
Look at him. (NOT Look him.)
Watch
Watch has a similar meaning to look at. It is mostly used to talk about things that change, move or develop.
I sat there watching them play.
The police have been watching their movements for three days.
Watch is the word normally used with TV.
He likes to watch TV for hours.
Both watch and see can be used to talk about TV programs and films.
I saw a good film yesterday. OR I watched a good film yesterday.