Boxing Day is a unique holiday that originated in Britain and spread throughout the world mostly through its colonies. It has a deceptive name that makes you think it's related to boxing. In fact, it's much simpler - that's what they call the day dedicated to giving and receiving presents. However, unlike Christmas, these presents are not given to relatives and friends.
The tradition of Boxing Day is to take to the streets and share money and nice gifts with those people who need them the most right now. Material and financial assistance to those in need is a great highlight of the Christmas week.
By the way, there are two versions of the origin of the holiday:
According to the first, wealthy families in Britain gave their servants leftover food, money and other gifts the day after Christmas as a thank you for their work. These were packaged in boxes, hence the name.
Another version says that the boxes were located in churches and monasteries, where caring people could put something for the poor into them. This variant is considered canonical in Ireland.
These days Boxing Day is celebrated in Britain, Ireland, the USA and some other countries. In Luxembourg and Europe, it is not yet so widespread, but that may change in the future.