Final answer:
A pushrod engine uses push rods for transferring motion to rocker arms and valves, while an overhead cam engine features the camshaft directly in the cylinder head. Both are types of internal combustion engines, which have played a crucial role in modern transportation and machinery.
Step-by-step explanation:
The type of engine that uses push rods to transfer motion to the rocker arms and valves is known as a pushrod engine. On the other hand, a camshaft in the cylinder head is typical of an overhead cam engine design. In the four-stroke internal combustion gasoline engine, heat transfer into work is carried out through a cyclical process where fuel-air mixture is compressed and ignited to generate power, making the piston move and rotate the crankshaft. This rotation then powers the vehicle or equipment the engine is installed in. The internal combustion engine revolutionized transportation and machinery by providing a compact and efficient way to generate power as opposed to the larger steam engines.