use of captcha why it used in every site before submit ?

Question

use of captcha why it used in every site before submit button ?

Akhil Garg · Answer

It prevents from DoS attack as well as it make sure that entries is done by human being

Suraj Sahoo · Answer

Hello Santosh Captcha is used to avoid robot entries into the database or the hack entries. http://security.stackexchange.com/questions/26094/why-do-we-need-captcha-in-what-case-we-should-use-it Look into the above link for more information from the discussion. Thanks

Michal Habalcik · Answer

hi to prevents various bot to autosubmit the form. Captcha should be guarantee that the form was submitted by a human.

use of captcha ,,why it used in every site before submit ?