The only 1 is call the maid of honour & Best man.
The others who help up is called the bridesmaids and the groomsmen.
maid of honor should be the 1 who take care of you during the whole wedding.
Like touch up, be there for you when you are nervous and get you some food so who won't go hungry and organize the bridesmaids.
Best man, to safe keep the wedding bands, organize the groomsmen, help groom to drink on banquet.