What is a

Internet users are often faced with a ...

When you submit a comment, or register with any resource, you are offered a special text box to enter numbers or letters in the picture. Or, you try to download the file you want with the file-sharing server. For links to the file, as a rule, you must enter the code shown in the picture, and click ...

CAPTCHA. ( English. - Completely Automated Public Turing test to tell Computers and Humans Apar) - an abbreviation of the long English expression, which in Russian sounds like ... In other words, it's a little problem, you simply decide to man, and the computer will not solve all or with great difficulty. Typically, this task on recognition of visual images. The term appeared in 2000.

In the most common version of CAPTCHA requires the user to enter the characters shown in the figure proposed in the garbled form ( with the addition of ... Less commonly used CAPTCHA, based on speech recognition ( as an alternative for people with visual impairments ).

Can also be used other bad algorithmic tasks, for example, to find out what's in the picture, note all the pictures of animals or answer a question related to the knowledge or the mentality of people ( eg, ...

CAPTCHA is used to prevent automated registrations and multiple message sending software robots ( bots ), t. e. challenge CAPTCHA - spam protection, flood and seizure of accounts.

Interestingly, although the CAPTCHA is designed to ...