The butterfly effect

@Cvankerkhove had a blog recently about the butterfly effect. The butterfly effect is basically the idea that every thing that happens has an effect on everything else so if one thing doesn't happen everything else could be different. This got me thinking about the idea of time travel and how things would change if you were to go back in time and interact with other people. With this idea in mind what would change? Would the time line that you went back to, continue on and basically start all over again by living out all of the changes that you made to it while the time line that you came from, continues to live out their time line? Or is their just one time line that is being altered? This idea of different time lines is kind of like alternate universes which is a cool concept and it makes me question the conciseness of us right now and how there could be multiple of you on different timelines.