Completely Automated Turning Test to Tell Computers and Humans Apart, better known as CAPTCHA, is a program that gives safety and security to your site. This program mainly generates test that only a human can pass but automated computer programs cannot. CAPTCHA can help you in a number of ways:
• It will allow only humans to post comments in your blogs and will therefore not be accessible by automated programs.
• It will protect your site from spam and email worms.
• It ensures that only humans obtain free email accounts offered companies like Yahoo, Microsoft etc. and does
not allow “bots” to sign up for innumerable email accounts.
• It is very effective to prevent abuse by automated programs in case of online polls as well and ensures that only
humans can vote.