CAPTCHA, distorted letters that people often encounter when filling out web forms found on an increasing number of websites, although it can be irritating to some users. They are for prevention from spammers and those who want to abuse Internet.

CAPTCHA stands for Completely Automated Public Turing Test Tell Computers and Humans Apart. As name implies, they are used to verify that a person, not a program that is behind submission.

Because human has better capabilities at decyphering visual information than computers, CAPTCHA is used in situations where spammers and others with malicious software can be used to abuse the Internet sites. For example, you can use spammers programs automatic links to submit spam to promote products through web forms. Or they can use these programs automatic creation of email accounts to comply providers such as Gmail and then use these accounts to send spam.

CAPTCHA often consist of distorted letters backgrounds making them harder to read. Since human brain is far better to recognize patterns in these situations than computers, a well-designed computer can still defeat CAPTCHA programs, most of the time. But spammers and other developing countries are becoming more sophisticated ways to defeat circumvent them.

Since the methods and algorithms used by those trying to circumvent the system becomes more and more sophisticated CAPTCHA has been difficult. While new ways of using photos, map reading and other methods developed. There is also a threat to turn off legitimate users if the process is cumbersome. You can search and get your own CAPTCHA download and many more informations and guide regarding CAPTCHA available in the Internet.

The only problems is computers’ development are evolving fast, they started to think like humans. Whatever computers evolved and as long as people use automated programs to the Internet for malicious purposes, CAPTCHA’s usage and sophistication are likely to grow side by side.