Pliers come in a variety of types and sizes. Some pliers reach tight spaces, while others lock down and not slip. Regardless of the type of pliers you own or use, all have similar features and a basic design that makes them part of the “pliers” family.
All pliers have handles that you squeeze to close the nose. Some pliers have electrically insulated handles to ensure that the user does not get shocked if the pliers touch a live electrical wire. Other pliers have ergonomic handles, designed to be comfortable to the user. Yet other pliers are only solid metal -- handle included -- like the vise grip type.
The nose of the pliers is the head or tip, where the actual gripping happens. When you spread the handles of the pliers, the nose opens; when you close them the nose clamps down on whatever you are gripping. There are many different types of noses. You have a blocked shaped nose which is standard. You have a needle nose which is a long nose that comes to a point so that you can reach into tight spots. Other heads are wide mouthed and have teeth to help with slipping like one used on metal piping. There are pliers with bent noses to get around tight corners.
One type of pliers uses a locking mechanism. When you squeeze the handle it locks the nose onto whatever it is grabbing; these are vise grips. At the bottom of the handle is a screw that allows you to set how wide the nose will open. If the nose is not wide enough, you'll find it difficult to squeeze the handles together. Set it just right for the pliers to clamp down tightly on what you are grabbing; they lock at the same time. To release the pliers from the locked position, use the lever on the inside of the handles that you squeeze as you are opening the handles. This will unlock the vise grips.
Some pliers come fitted with a cutter to cut wires or other thin metals. This cutter is either a flat sharp blade or serrated. Some pliers have the cutter in between the jaws of the nose so that when you squeeze them, if the you set the wire on top of the cutter, it will cut it. Other designs have the cutter at the top inside of the handle. With this design, you would slip a wire in between the handles and squeeze to cut.