Because women's hands are smaller than mens, the grips on women's clubs are smaller in diameter so that women can properly grip the club.
Women's irons have a much softer flex, and the clubhead may be slightly heavier (though the club is lighter overall). The shafts are also shorter as women are shorter in stature than men. This combination is designed to make the most of women's slower swing speeds.
Women's woods have a higher degree of loft and are lighter than men's woods. In addition, there is a bigger range of women's woods, going up to a 13-wood, which is a great replacement for a long iron as it is easier to hit with.
Women's drivers have a minimum 12-degree loft, versus 9-11 degrees on men's drivers. The higher loft helps women to get the ball in the air more easily off the tee. Women's drivers are usually also lighter than men's. These differences allow women to get better distance, speed and a higher trajectory off the tee.
Women's clubs tend to have graphite shafts, which are much lighter than steel. Men's clubs usually come with a choice between graphite and steel shafts. Graphite shafts allow for a softer flex which, in turn, leads to better club head position.