the ceremony rehearsal is a practice play of the wedding ceremony at your venue, you go through the order of the ceremony, practice walking & wedding party places, sometimes rehearse ceremony readings. the rehearsal dinner is typically a private dinner before the wedding day, with you & the groom2be along with your parents, officiant & wedding party and sometimes out of town guests. many people do toasts, gift thank you gifts, or just have a nice time with their loved ones.