What is CAPTCHA??

CAPTCHA stands for Completely Automated Public Turing [test to tell] Computers and Humans Apart. Although you may not be familiar with this acronym, it’s very likely that you’ve experienced one on various web sites. A CAPTCHA is a challenge-response test used with computers to determine if a user is human or not. Whenever you are asked to type in a series of letters and numbers, often distorted, on a web page, you have been presented with a CAPTCHA test.

CAPTCHAs may be used to limit access to web services such as banking and e-shopping sites to “real people,” and to try and block access by computer “bots” masquerading as people. They are also used on other web sites such as Yahoo mail. In short, they are a useful ally in the effort to make the web secure.