What's the difference between Mayonnaise & Miracle Whip?

The Dilemma: Two thick white dressings with similar flavor in similar-looking jars are bearing down on you from your refrigerator, and you’re asking yourself just one question: "Do I feel lucky?" Well, do ya, punk?
People You Can Impress: deli-goers and anyone killing time in the checkout line.
The Quick Trick: Taste them both side by side. The sweeter one is Miracle Whip.
The Explanation: In 1756, the French under Louis François Armand de Vignerot du Plessis, duc de Richelieu, captured Mahón on the Spanish-held island of Minorca. In honor of this victory, the duc’s chef created a new dressing for his master: Mahonnaise. It wasn’t until 1905, however, at Richard Hellmann’s New York deli, that Americans got to taste the goods. But boy, did it catch on! Within seven years, he’d mass-marketed the condiment as Hellmann’s Blue Ribbon Mayonnaise.
To be frank, mayo is one of those love-it-or-hate-it things. The lovers know that, in its most authentic form, mayo’s a pretty simple affair: raw egg yolks, oil, lemon juice or vinegar, and spices. Not much room for improvement.
But in 1933, Kraft Foods though differently. Inventor Charles Chapman’s patented emulsifying machine allowed regular mayonnaise to be evenly blended with cheaper dressings and more than 20 different spices (plus sugar). The result was Miracle Whip, which debuted at the 1933 Chicago World’s Fair. Promising to create "Salad Miracles with Miracle Whip Salad Dressing," the Whip was an instant hit (Note: It’s not known if the dressing is responsible for any non-salad-related miracles.)
The main difference between Miracle Whip and mayonnaise are the sweeteners: high-fructose corn syrup and sugar are the fourth and fifth ingredients, respectively, of Miracle Whip.

Yeah – that is what caused the great 15-yr-old-meltdown of June 12, 2009. Now – to repair my eardrums…..And for the record – she HATES miracle whip (I love it) and she loves mayonnaise (I hate it). I still think it’s responsible for miracles. No matter what they say. A sandwich just isn’t a sandwich without the great taste of miracle whip salad dressing…..right Bubby?