Can somebody explane me Inception? Pls.?

Leonardo's wife is dead, suicide by jumping from a ledge on high building. Her spirit/personality is still alive in the dreamworld limbo that they were trapped in for 50+ subjective years in an earlier experiment. She can still affect and inhabit his dreamworld when he travels there. She wants him to stay in limbo with her. He finally breaks the chain that ties them together at the end of the film, so he can live with their children, but the end of the film leaves it open as to whether this is another dream.