You’ve seen them in some form on almost every website where you input data, such as contact forms or comment boxes.

Some can be annoying, but they are there to serve an important service.

They reduce spam by distinguishing human from machine input.

What does CAPTCHA stand for?

CAPTCHA stands for “Completely Automated Public Turing test to tell Computers and Humans Apart”.

The future of CAPTCHA

As the issue of online security grows evermore potent, maybe one day soon fingerprint recognition will be the norm to log into your favourite services.