Why are "&" and "and" treated differently?

[internetheaven]

If you use & or and in a keyphrase you get different results. Just curious.

[tedster]

Google shows 11 million results for the word "and" but 7 million for the ampersand character.

I do see some semantic matching between the two, but it can never be an exact equivalence. For example, [ ] is certain not the same as [and nbsp]

[TheMadScientist]

Along the same lines as tedster's post...
They're not the same, and can mean very different things in a search:

When working with URLs this might be important:
encode &

and is completely different than:
encode and

[Lame_Wolf]

It also treats apostrophes and hyphens differently.

[tangor]

There's the literal aspect which brain dead, but very fast processing, algos deal with. How many ways can the ampersand be coded? Quite a few. And let us not get started on endash, emdash and ellipses!

[signor_john]

"Briggs & Stratton" doesn't necessarily mean the same thing as "'Briggs' and 'Stratton'."

(Mind you, a lot of people--including me--are as likely to type "briggs and stratton" as they are to type "briggs & stratton" if they're looking for information on small engines for lawn mowers and the like. I wonder if search engineers spend much time agonizing over the sweet spot between literal correctness and adjusting for user behavior?)