While turning the steering wheel there is a whining sound from the motor. What is it?

You can hear your power steering pump working and if it's whining, it may be low on fluid.
Check the fluid level with the engine running and be very careful of moving or rotating parts.
Locate the pump and check the level (the cap will usually have a dipstick to measure the level attached to the cap and you read it the same way as your engine oil dipstick). DO NOT overfill the pump as it will just leak out and cause other issues.
If the level is very low, top it up then work the steering from side to side a few times then recheck the level. Careful, power steering fluid can get very hot!!
If the fluid in the pump looks dark or black, take the vehicle to your local mechanic and have the fluid replaced and the system flushed.

Most common problem is low power steering fluid, if this does'nt help the power steering pump may be going bad, try adding fluid first

Could be power steering pump. make sure it has enough fluid and the belt is tight enough.

Sounds like the power steering pump. I would check for low fluid first. If it is full and still makes the noise then it needs to be replaced. Make sure if it is low that you only add POWER STEERING FLUID.

Could be power steering pump, if it only happens when turning wheel, go out to vehicle crank it up and just turn wheel to left all the way , then right all the way when it gets to the end left or right if it is whining that is your p/w steering pump that is bad.