Power steering allows you to turn your steering wheel and axles with minimal force. Without a power steering system, you would not be able to turn your vehicle without some extreme force. The first automobiles did not have this system, making it difficult for just anyone to get behind the wheel.
Power-assisted steering systems are mainly hydraulic or electric, or a combination of both. If you have ever experienced losing your steering assistance, you know how difficult it is to drive your vehicle without it.