It's a CAPTCHA

We've all seen these things, set up at various websites to foil computers posing as real humans.

But did you know they have a name?

They're CAPTCHAS. That's a somewhat contrived acronym for "Completely Automated Public Turing test to tell Computers and HumansApart" coined in 2000 by the geeks at Carnegie Mellon University and IBM who created them.

The Turing test is a proposal for a test of a machine's ability to demonstrate intelligence. Described by Alan Turing in the 1950 paper "Computing Machinery and Intelligence." 

So now you know.