Question

how does captcha help in security

Answer 1

The technology is used mostly to block spammers and bots that try to automatically harvest email addresses or try to automatically sign up for or make use of Web sites, blogs or forums. CAPTCHA, whose users include Yahoo and Google, blocks automated systems, which can't read the distorted letters in the graphic.

Answer 2

Answer:

CAPTCHA technology authenticates that a real person is accessing the web content to block spammers and bots that try to automatically harvest email addresses or try to automatically sign up for access to websites, blogs or forums. CAPTCHA blocks automated systems, which can't read the distorted letters in the graphic