It is an shape structure whose one end is connected to piston and other one to crankshaft. The piston side end of connecting rod has hole in it. And we have also got a hole in pistons cylindrical structure just beneath the piston rings. So we align this hole with connecting rods hole and put a wrist pin through it. Wrist pin act as a bearing and connecting rod can move like pendulum beneath piston, though pistons cylindrical structure is gonna limit its motion. To make sure that wrist pin should not move from its position it is restricted by snap ring at both sides.

Other end of the connecting rod can be split into two parts. First is semi-circular journal bearing seat, which is placed over crankshaft after installing the half part of journal bearing, in the seat. Other half is journal bearing cap. These two parts are bolted together, holding crankshaft in between.