Pliers are a combination of a wedge and a lever. It is a simple machine that consists of two arms connected by a pivot point. The pointed jaws of the pliers act as a wedge, allowing them to grip objects tightly, while the handles of the pliers act as a lever, allowing you to apply force to the jaws to close them around an object.
The lever action of the pliers allows you to use relatively little force to generate a relatively large amount of clamping force, making them a very useful tool for gripping, holding, and manipulating objects.

Pliers are a type of tool that consists of two levers that are designed to allow the user to grip and hold objects tightly. The jaws of the pliers act as the load, the pivot point where the jaws are attached to the handles acts as the fulcrum, and the handles of the pliers act as the effort.
When the handles are squeezed together, the levers transmit the force applied at the handles to the jaws, providing a mechanical advantage that enables the user to clamp objects with relatively little effort. This lever action is what makes pliers a useful tool for gripping, holding, and manipulating objects.

Parts of a Lever
Pliers are an example of a first-class lever, as the fulcrum is located between the load and the effort. In this type of lever, the force applied at the effort is multiplied several times before it is transmitted to the load. When the handles of the pliers are squeezed together, both levers exert force in opposite directions toward each other, resulting in a clamping action on the object being held.

Simple Machines
Pliers are just one example of a simple machine. There are five other types of simple machines: the wheel and axle, pulley, inclined plane, wedge, and screw. These simple machines can be combined to form complex machines, such as a wheelbarrow (which is a combination of a lever and a wheel and axle) or a screwdriver (which is a combination of a lever and a screw).
Understanding how simple machines like levers work can be useful for a variety of purposes, such as designing and building new tools or machines, or simply understanding how everyday objects like pliers function.

How do pliers work as a lever?
Pliers work as a lever by using the principle of leverage. A lever is a simple machine that consists of a beam or rod that pivots around a fixed point called a fulcrum. When you apply force to one end of the lever, it produces a mechanical advantage, allowing you to lift or move a load at the other end of the lever.
In the case of pliers, the fulcrum is the pivot point where the jaws of the pliers are attached to the handles. When you squeeze the handles of the pliers together, you apply force to one end of the lever (the handles).
This force is transmitted through the jaws of the pliers to the object being clamped, producing a mechanical advantage that allows you to grip and hold the object with less effort. The longer the handles of the pliers, the greater the mechanical advantage, and the easier it is to use the pliers to clamp an object.