A wedge is best described as:

A wedge is best described as an inclined plane that moves and splits objects. This definition highlights the essential function of a wedge, which is to exert force on an object to separate or split it apart. The inclined plane aspect of a wedge allows it to convert a downward force into a lateral force, enabling it to effectively penetrate and divide materials.

This mechanism is evident in everyday objects such as knives, axes, and chisels, all of which utilize the wedge shape to facilitate cutting or splitting actions. By applying force at the thicker part of the wedge, the sloped surfaces drive into the material, thereby creating two separate sections.

In contrast, a stationary inclined plane simply refers to a fixed surface that facilitates movement without the splitting function. A flat surface used for balance does not capture the essence of a wedge's action. Lastly, an object that rotates around a fulcrum describes a lever, which functions differently compared to how a wedge operates. The unique motion and effectiveness of a wedge in separating objects make its definition as an inclined plane that moves and splits objects accurate and applicable.