Christmas arrived in Oaxaca and in general in Mexico by the Spaniards, since it is a tradition of the old continent.
The true meaning of Christmas is the birth of Jesus, the word comes from the Latin nativitas meaning birth.
Christmas was implemented as part of the indigenous evangelization, and curiously coincided with the Aztec celebration of the birth of Huitzilopochtli so it was easier to introduce these beliefs, but once again formed a mestizaje and incorporated indigenous characteristics to the celebration.