Captcha Definition
Captcha is the abbreviation of “Completely Automated Public Turning test to tell Computers and Humans Apart”.
What is Captcha?
Captcha is some kind of a test or a task that human user will perform easily while a bot or an automated script should find it difficult to carry out as well as time-consuming.
Captcha tests are used in situations in which websites owners need to be sure that the user is not a bot and as such doesn’t intend to misuse their online platforms and/or the free services they offer (such as free blog and forum registration or free e-mail accounts).
By using Captcha program the server prevents e-mail spamming, commercial promotion in forums, vandalism and so on.
Captcha System
The Captcha system is based upon visual perception, analogical human intelligence or sensual skills.
The most common Captcha control contains an image of distorted letters or numbers and other signs that the user need to copy. Sometimes a serial of images appear of which a single subject should be defined, sometimes a question to be solved appears, all to ensure security and protection from automated abuse.
