Most people attending a wedding only know one of the couple. It is natural for them to sit on that side and with their relations and friends that they know, rather than sitting in amongst strangers. It is also natural for the immediate family members to sit together on the side of their family member that is getting married. Behind them will be their relations and friends. If you were going to a wedding of a family member or relation, you would naturally sit with your family. If you were not part of the immediate family and only knew one of the couple, you are more likely to sit with friends or relations of yours, who are more likely to be sitting on the side of the person that you know. It can also be symbolic, in that the couple come together as two separate individuals and so the people that know them sit separately, like they often light two separate candles before the ceremony and then light one candle together after they are married to symbolise they are now one. Later in the day there will be plenty of opportunity for the people to mix.
If you are the bride and groom of the wedding at the church...
the families that produced the bride and groom
There's NO tradition involved, since every wedding is different.
* The bride and groom say exchange their vows in front of the altar.
by the families of the bride and groom
the families that produced the bride and groom
Meeting the Fockers
The bride walks down the aisle to meet the groom at the alter in a church wedding.
At the wedding where the bride and groom should be introduced as 'man and wife' or 'bride and groom' is at the church when the Minister, etc. pronounces 'I now pronounce you man and wife' and again when you enter the reception hall you should be introduced as 'Mr. & Mrs. _________.' If there is a reception line at the hall then the bride and groom will be introduced together. Toasts at the head table will be directed at the bride and groom. The bride and groom do not have to be together to be introduced once they are mingling with guests at the wedding reception.
they stand on the side of their family and where the guests are seated
The bride's relatives are on the left and groom's relatives are on the right. The ushers are to escort relatives (including grandmothers) down the aisle and the bride's grandmother would be on the left; the groom's grandmother on the right. It just depends whether the bride or groom's grandmother gets to the church earlier then they will be seated at that time.
the bride and the groom is first, then the bride and her father, and then the groom and his mother. After that the bride dance with her new dad and groom dance with his new mom.