between vs among

among

preposition

 1 surrounded by someone or something; in the middle of someone or something

 a house among the trees 
They strolled among the crowds. 
I found the letter amongst his papers. 
It's OK, you're among friends now.

 2 being included or happening in groups of things or people 

An American woman was among the survivors. 
He was among the last to leave. 
This attitude is common among teenagers. 
“What was wrong with the job?” 
“Well, the pay wasn't good, among other things.
”Discuss it among yourselves first (= with each other).

 3 used when you are dividing or choosing something, and three or more people or things are involved 

They divided the money up among the children.

 

between

preposition

 1 in or into the space separating two or more points, objects, people, etc.

 Q comes between P and R in the English alphabet.
 I sat down between Melinda and Sasha. 
Switzerland lies between France, Germany, Austria, and Italy. 
The paper had fallen down between the desk and the wall.

 more info :  http://oaadonline.oxfordlearnersdictionaries.com/dictionary/between