Karma (car-ma) is a word meaning the result of a person's actions as well as the actions themselves. It is a term about the cycle of cause and effect. According to the theory of Karma, what happens to a person, happens because they caused it with their actions.

What ever you do, good or bad
The universe will send it back to you in a purpose. 
Maybe to make you understand more about life or to realize the essence of life.

There is this known phrase about karma ". What goes around, comes around.
For me this means what ever you throw away will come back to you. 
You do good then you'll receive good things.
You do bad then you'll be punished relatedly or a result of the bad thing that you did