С Рождеством!

I don't understand this holiday in Russia. Is it merely a religious observation, or do people also exchange gifts on Orthodox Christmas as they do on New Year's? Congratulations to those who celebrate! I'm not sure how the Orthodox church observes Christmas day, or if it varies from the Christian rituals in the USA and Europe on 25 December, but I hope everyone has a festive day! Cheers from the USA! :) Please share Orthodox Christmas traditions in comments. I'm not religious and don't observe these holy days, but is interesting to learn about cultural distinctions for celebration.