Just a quick fact for you. In addition to the many different types of engine out there, there are different ways of seating an engine in the engine bay.
As we know from earlier posts, at the bottom of the engine cylinder block is a crankshaft which connects to the connecting rod and piston. So imagine your crankshaft as a long bar with a left and a right side.
If the left side of your crankshaft faces the left side of the vehicle and the right side of the crankshaft, the right side of the vehicle, then your vehicle has a transverse engine. The crankshaft is said to be perpendicular to the long axis of the vehicle.
If the crankshaft faces front to back, then your vehicle has a longitudinal engine. The crankshaft is said to run parallel with the vehicle.