A slider in baseball refers to a type of pitch that can be thrown by the pitcher. A ball that can be considered a slider is one that is thrown faster and smoother than a curveball. Curveballs can sometimes be mistaken as sliders and vice versa due to their similarities in the way that they fly. A slider’s main purpose is to deceive the batter.
A slider is even held like a curveball, but with a few minor adjustments. It is spin as it is thrown, and the movement is made by snapping the wrist in order to project it.