December is a month of many holidays, both religious and secular (non-religious).
Christmas and Hanukkah started as religious holidays. If you know that someone celebrates Christmas, you can wish her “Merry Christmas!” If you know that someone celebrates Hanukkah, you can wish him “Happy Hanukkah!” If you aren’t sure what someone celebrates, you can say “Happy Holidays!” or “Season’s Greetings!”
Schools and offices often decorate for the holidays. They use evergreen branches which show that there is always life, even in the “dead season” of winter.
Coworkers will sometimes do a gift-exchange. They decide on how much the gifts can cost. Then, they put everyone’s name into a bag and pull out one. They buy a gift for the person whose name they have chosen. Sometimes this exchange is called “Secret Santa.”
Another popular gift exchange is called a “White Elephant Gift Exchange.” People wrap one small gift or object from their house, usually something funny or strange. Then they draw numbers to see the order in which they open the gifts. Other people can “steal” these gifts after they have been opened, exchanging the gift they chose instead. Usually there is a limit to how many times the same gift can be “stolen.”
New Year’s is a secular holiday, meaning that it has no connection with religious affiliation. We can wish anyone a “Happy New Year’s!”
Kwanzaa was a holiday that was started in the 1960’s to honor African-American heritage in the U.S. Not many people celebrate Kwanzaa, but if you want to know more about it, you can read the article: “Why You May Not Hear “Happy Kwanzaa.”