Exactly What IS Boxing Day?

I wasn't in Toronto on December 26th this year, but everywhere I went Americans were making some comment about it being Boxing Day back in Canada - and I should know what that is because I live in Canada now?  I had heard of Boxing Day when I lived in the US, but didn't pay much attention.  However, in Ontario, Boxing Day is actually a statutory holiday, so I did some digging to figure out what I could about Boxing Day hoping not to look so ignorant when people make comments in the future.

So, just what is Boxing Day?  I can't find a clear-cut answer about where it came from, and even according to Wikipedia the exact origin is unknown (What?!  If Wikipedia doesn't know, I generally assume nobody knows!).  It definitely stems from the British as it is also celebrated in the UK, Ireland, South Africa, Australia, New Zealand, and some Commonwealth nations.  This makes sense as you'll find a lot of British influence in Canada.  Why they started celebrating it seems to have something to do with boxes (not the sport Boxing) of gifts and/or money for the poor or people in service jobs.  It may have also been a day when servants got the day off to go see their family after helping to make the holidays go smoothly. 

Present day, it is celebrated in Ontario with a day off of work for most and lots of shopping deals.  Some deals last the whole "Boxing Week" but the mad rush to the mall for deals could be similar to Black Friday in the US.   Check out these links from some local papers covering the day:  http://simcoereformer.ca/ArticleDisplay.aspx?e=2907054 and http://www.thestar.com/news/article/912302--boxing-day-madness-hits-toronto

Boxing Day Morning Line-Up (Picture from the Toronto Star)

I'll keep researching the holiday so I'm ready for next year, but I'd love to hear more about how you celebrate Boxing Day or any more information you have on the history and origin!  Help a newcomer out!