If you notice some clunks, knocks or squeaks when you turn the steering wheel, something in the system is causing friction that needs attention; if you notice moaning or whining, the issue is likely to be in your power steering system. In either case, this is a problem that needs attention because steering properly is vital for operational safety.
Normally, when the steering wheel is turned, the process should be smooth and silent. Friction inside the system sometimes appears within the steering column if something has come loose and is hitting it when you turn. Occasionally, the steering gear requires lubrication or repair. If steering linkage parts come loose, friction is a possible result. In the wheel well, it is possible for part of the undercarriage to come loose and rub the tire. Suspension parts that are in need of replacement also cause friction at times.
Problems within the power steering unit cause even louder noises, but they often do not happen until you turn the wheel as far as you can in one direction. If the power steering drive belt is loose or damaged, whining often gets quite loud. Sometimes air gets into the power steering fluid system, and the remedy for that is to bleed the system. If power steering fluid is low, fill it to the indicated line. The last possibility involves a damaged or loose power steering system which needs replacement or repair.