What type of brakes do power brakes typically refer to?

Power brakes typically refer to hydraulic brakes. This type of braking system uses fluid pressure to assist in the application of the brakes, making it easier for the driver to engage the brakes without needing to exert as much physical force. Hydraulic brakes are common in modern vehicles due to their efficiency, effectiveness, and their ability to provide greater force than mechanical systems.

While other types of brakes, such as pneumatic, disc, and drum brakes, play significant roles in various braking systems, they do not relate directly to the concept of "power brakes" as understood in most automotive contexts. Pneumatic brakes are often used in heavy-duty vehicles and rely on compressed air, while disc and drum refer to the configuration of the braking components but can be either hydraulic or non-hydraulic. However, in the context of "power brakes," it is specifically the hydraulic type that is designed to assist the driver effectively and is widely used in passenger vehicles.