I am not qualified to write something on stuff like this, hence I pull out the definition of Chaos Theory straight from our beloved Wikipedia.
“Chaos theory is a field of study in mathematics, physics, and philosophy studying the behavior of dynamical systems that are highly sensitive to initial conditions. This sensitivity is popularly referred to as the butterfly effect. Small differences in initial conditions (such as those due to rounding errors in numerical computation) yield widely diverging outcomes for chaotic systems, rendering long-term prediction impossible in general. This happens even though these systems are deterministic, meaning that their future dynamics are fully determined by their initial conditions, with no random elements involved. In other words, the deterministic nature of these systems does not make them predictable. This behavior is known as deterministic chaos, or simply chaos.”
BBC has a series of videos which try to shed some light on this misunderstood part of science which indeed is a very interesting and fascinating field of study.
Many thanks to all the people involved in making of the video and uploading it onto Youtube.