Captcha :
Captcha is a type of word picture that is ambiguous.The lines of words are irregular. Captcha is mainly used in websites. Captcha is mainly used to protect against hackers. Hackers use various programs and robots to hack and they cannot read this Captcha.A human can easily see and write the Captcha, but a robot cannot. So web sites use Captcha to protect themselves from hackers. Captcha must be used to power a web site.Below are some examples of Captchas.
reCAPTCHA
reCAPTCHA is the modern captcha. This is not a text captcha. In modern age hackers also use their modern technology, so reCAPTCHA is a modern technology for modern age. With reCAPTCHA you can keep your website virus free. reCAPTCHA has become very popular nowadays.You can also earn from reCAPTCHA. Various web sites work with reCAPTCHA. They provide reCAPTCHA to various web sites.
