There are a number of variated definitions for the term "butterfly effect". According to wikipedia, the butterfly effect is defined by the passage below.
"The butterfly effect is a metaphor that encapsulates the concept of sensitive dependence on initial conditions in chaos theory; namely that small differences in the initial condition of a dynamical system may produce large variations in the long term behavior of the system. Although this may appear to be an esoteric and unusual behavior, it is exhibited by very simple systems: for example, a ballplaced at the crest of a hill might roll into any of several valleys depending on slight differences in initial position. The butterfly effect is a common trope in fiction when presenting scenarios involving time travel and with "what if" scenarios where one storyline diverges at the moment of a seemingly minor event resulting in two significantly different outcomes."
After searching for the term on multiple websites, I have gathered facts that define the butterfly effect as a certain type of metaphor that incorporates different types of scenarios and uses them in a "what if" fashion. A common example I found while looking up this definition was "if a butterfly is flapping it's wings, it might change the wind force somewhere around the world.