This post is from a low-reputation account and contains an unverified outbound link. Be cautious before clicking external links.
Ref
Why is today called Boxing Day, how did this day come about and where can it be traced to?
Boxing Day is a holiday celebrated on the 26th day of December, a day after Christmas Day.
Origin
Boxing day has been traced to have originated from the United Kingdom in the middle of the nineteenth century under Queen Victoria.
When it all began in Britain, the idea behind boxing day, was to relief their servants, on this day, servants of the wealthy were given off day to visit their families and loved ones, they also in turn present this gifts to there families and loved ones.
WHY IS CALLED BOXING DAY
December 26 was the day in the time past when Lords shared boxes to their servants, this boxes are often filled with all sorts of gifts, cash, foods and some items remaining from Christmas supper to their subjects, that have worked on Christmas day, in appreciation for the wonderful services rendered through out the year.
Ref
Boxing day has evolved to be a popular holiday in the United Kingdom and in many countries of the world, this day has turn to a day for watching sports such as football and cricket, visiting of friends and families and shopping.
Ref