The ceremonious entry of the wedding party at the beginning of the wedding ceremony is known as the procession.
Traditionally, bridesmaids and, sometimes, groomsmen walk down the center aisle of the ceremony site in a specific order or formation.
This procession is accompanied by music known as the processional.
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Merriam-Webster Online Dictionaryprocession
a) a group of individuals moving along in an orderly often ceremonial way
b) - succession sequence
a) continuous forward movement - progression
b) - emanation the Holy Spirit's procession from the Father
archaic to go in procession