What is the difference between chief bridesmaid and maid of honor?

No, a bridesmaid and a maid of honor are not the same thing. A maid of honor is a higher role than that of a bridesmaid; consider a maid of honor to be for the bride what the best man is for the groom. The maid of honor is typically responsible for assisting the bride with anything during the wedding planning process and is most notable for planning and paying for the bachelorette party. The maid of honor is also responsible for helping with the bridal shower (though bridesmaids are expected to help with the bridal shower, too). Finally, the maid of honor is responsible for making a speech at the wedding reception.