how is a woman's voice diferent from a man's?
All the answers are correct. I will give a combined answer of all the above:
Women's voice is higher in pitch than men's voice.
What is pitch?
A sound which has a higher frequency is heard as being higher in pitch than a sound of lower frequency.
Why?
Human 's have a voice box called larynx in our throat. Two ligaments known as vocal cords are stretched across the larynx in such a way that it leaves a narrow slit between them to allow the lungs to force air through them to produce sound. The vocal cords vibrate when air is forced through them. When vocal cords are light and thin, the voice produced is of high frequency. On the other hand, when vocal cords are loose and thick, the voice produced is of low frequency. Hence, women have a shorter vocal cord than that of men, so the frequency of a woman 's voice is high and the frequency of men 's voice is low.