The con rod is a rigid rod structure in the car engine which connects the crankshaft to the piston. The movement of the piston makes the crankshaft turn. The connecting rod plays an important role in working to provide drive from the piston to the crankshaft where this power is changed into the rotational force required to make the wheels of the car move. Connecting rods have a 'big end' and a 'small end' and are usually manufactured from steel, titanium or aluminium alloys.  

The big end of the connecting rod attaches to the crankshaft and the rotational movement of these two connected parts is aided by the big end bearing. The big end bearing has a supportive role and functions to allow the rotating movement of the crankshaft and the crank rod journals/crank pins while decreasing the amount of friction produced between the linked moving parts. The big end bearing coils around the crankshaft secures the crankshaft in position while enabling the rotating mechanism of the crankshaft. It is bolted to the connecting rod at the big end with the smaller end of the connecting rod attached to the piston with a bearing enabling rotation on this end also. The small end of the connecting rod can have either a solid or a split eye. Rod ends are vehicle specific meaning the rod ends will provide you with a part that's compatible with the make and model of your vehicle.

Essentially the connecting rod with the big end bearing and small end bearing/connecting bush allows power from the piston to be transmitted to the crankshaft.  

Working under continued pressure transferring the load exerted by the piston the connecting rod can crack, break or bend and can come loose from the piston or crankshaft. This can happen when the big end or small end bearing wears and detaches from the con rod causing the con rod to disengage from the crankshaft and piston in engine failure. The connecting rod can also suffer from rust and collision damage. A speedy replacement of the rod ends when they fail is recommended to avoid further associated damage to other components. When replacing this part, the rod ends will ensure you get a part that's specifically designed for the make and model of your vehicle, providing perfect compatibility.