A four-cylinder engine is a type of internal combustion engine that has four cylinders arranged in a line or in a configuration like a V. This design allows for a balance between power and fuel efficiency, making it popular in many vehicles, including compact cars and sedans. Each cylinder contains a piston that moves up and down, creating the power needed to turn the engine's crankshaft. These engines are known for their lightweight and compact size, which contributes to better handling and improved fuel economy. Many modern four-cylinder engines also feature technologies like turbocharging to enhance performance without significantly increasing fuel consumption.