Best Man
He acts as the groom's personal aide and advisor through all stages of wedding planning. He's a fashion consultant, bachelor-party master of ceremonies, and in charge of the groomsmen. His duties include (but aren't limited to): getting the groom to the ceremony on time; giving the officiant his/her fee after the ceremony; signing the couple's marriage license; and holding the bride's ring at the altar. Traditionally, he will give the first toast to the bride and groom at the reception.

Bride
The bride's duties are to plan all aspects of the event with the groom. Her goal should be to relax and have as much fun as possible.

Bridesmaids
These are female friends and family members who form the bride's entourage. They are a support team for the maid of honor, helping with pre-wedding tasks (i.e. addressing invitations, making shower favors, planning the bachelorette party, and more). Bridesmaids are often expected to be the first on the dance floor and mingle with the guests.

Father of the Bride
In addition to funding most of the wedding, the Father of the Bride’s chores might include airport duty, coordinating maps/directions to the wedding site, scouting potential locations, giving tips to wedding day staff, and a variety of toasting and hosting tasks. Traditionally, he also walks the bride down the aisle at the ceremony and “gives her away”.

Father of the Groom
In terms of cost contribution, the groom's dad pays for a few major items, notably the rehearsal dinner. He might also fulfill numerous dancing, toasting, and other "manly" obligations (i.e., escort elderly women, move tables, address problematic service). It's nice, also, for him to check in with the bride's dad occasionally to offer moral support.

Flower Girl
A girl aged 3-8 who walks down the aisle before the bride, scattering flower petals from a basket (or carrying a bouquet). Most flower girls sit with their parents after completing their walk.

Groom
He's the bride's wedding planning co-pilot, responding to all of her various requests. Chief responsibilities may include (but aren't limited to): heading up the band and DJ selection process, coordinating limo details, booking rooms for out-of-town guests, and doing most of the honeymoon legwork. He also marries the bride. His goal should be to make the bride have as much fun as possible.

Groomsmen
These are male family and friends who assist the groom in planning and preparing for the big day. Their chief responsibility is to help the best man plan and pay for the bachelor party. It's also common to have groomsmen serve as ushers, leaving their posts in time to enter with the rest of the bridal party.

Honor Attendants
The best man (see above) and the maid of honor (see below) are considered honor attendants. They may prefer to go by this title, replacing gender-specific references.

Junior Bridesmaids/Junior Groomsmen
Young members of the wedding party (aged 9-16) who will attend all major functions and fulfill the same responsibilities as other members. Young women can wear age-appropriate versions of the bridesmaid dresses and young men may be dressed in tuxes.

Maid/Matron of Honor
The bride's right-hand woman during the planning process, providing support as needed. The maid of honor coordinates the bridal shower and handles numerous wedding day details, which might include toasting the bride and groom, signing the marriage license, adjusting the bride's train and veil at the altar, holding her bouquet during vows, and collecting gift envelopes at the reception. She also should help the bride get dressed. She is the last bridesmaid to walk down the aisle before the bride.

Mother of the Bride
The bride's mom may serve as wedding planner, guest list moderator, traditional reception hostess, fashion critic, and cheerleader. Other duties include researching family and ethnic traditions, attending the shower and rehearsal dinner, and dancing at the reception. The nature of the bride's mother's role is entirely up to the bride.

Mother of the Groom
The groom's mother can assume any of the bride's mom's responsibilities. She attends the shower, and is escorted down the aisle during the prelude. She dances with the groom during the mother/son dance.

Officiant
The clergy member or official who performs the marriage ceremony. Examples include a priest, a rabbi, a minister, or a justice of the peace.

Ring Bearer
A young boy aged 4-8, who walks down the aisle just before or with the flower girl, carrying a small decorative pillow with two rings tied to it (usually fakes, in case they are lost).

Ushers
Men who escort guests to their seats before the ceremony. Ushers are often employed in addition to groomsmen.