Compound machines are systems that incorporate two or more simple machines into their design. A pair of scissors is a compound machine that incorporates both the lever and the wedge into its design.
The scissors' handles are connected in the middle, and the point of connection acts as the fulcrum of a lever. The squeezing force exerted against the handles is then transmitted to the scissors' blades. The blades are wedges, another type of simple machine. A wedge is a sharpened inclined plane that concentrates force along a narrow line to cut into and separate the object it is used against.