There are a lot of reasons as to why Christmas is celebrated each year and why it is so popular. One of these is the eucharist one that is a mass service that focuses on the fact that Jesus died for his people and then came back for the better. Therefore, the service focuses on his being back and then helping others. This mass continued for well past midnight and hence is called Christmas.
At the Christmas celebrations, people all over the world celebrate the birth of the Lord and traditional festivities can be observed in most of these nations. Since people of faiths other than Christianity also focus on celebrations, it is a multicultural festival that is well-loved by all.