As you know, Christmas is a celebration of Christ’s birth.  But the date of Christ’s birth isn’t mentioned in the New Testament.  Instead, early in the first millennium, Christians took over December 25 (the Roman festival of Saturnalia) to celebrate Christ’s birthday.  It’s become a day of devotion no matter what date Christ was actually born. 

In contrast, the story of “The ‘Three Magi’ is an important part of the New Testament.  Historically, the magi were priests of the Zoroastrian religion of Persia.  In the New Testament, the Three Magi see a bright new star in the night sky.  They recognize it as a sign that the son of God is about to be born, so they follow it westwards until they find the newborn baby Jesus.  They then present precious gifts to the baby. 

At that time, there were two great monotheistic religions, Judaism and Zoroastrianism.  So this was seen as an important symbol of respect from one religion to the other.

I’m told that some Chinese Christians believe that one of the Three Magi was instead Liu Shang, a court astrologer of the Han dynasty.  But this is beyond my expertise to evaluate.