Captcha

A captcha is program used to confirm {that a} human, slightly than a pc, is getting into information. Captchas are generally seen on the finish of on-line forms and ask the person to enter textual content from a distorted image. The textual content within the image could also be wavy, have traces by way of it, or could also be extremely irregular, making it practically unimaginable for an automatic program to acknowledge it. (Of course, some captchas are so distorted that they are often troublesome for people to acknowledge as effectively.) Fortunately, most captchas permit the person to regenerate the image if the textual content is simply too troublesome to learn. Some even embrace an auditory pronunciation characteristic.

By requiring a captcha response, site owners can forestall automated applications, or “bots,” from filling out forms on-line. This prevents spam from being despatched by way of web site forms and ensures that wikis, equivalent to Wikipedia, are solely edited by people. Captchas are additionally utilized by web sites equivalent to Ticketmaster.com to ensure customers do not bathroom down the server with repeated requests. While captchas could also be a minor inconvenience to the person, they will save site owners loads of trouble by heading off automated applications.

The title “captcha” comes from the word “capture,” because it captures human responses. It may additionally be written “CAPTCHA,” which is an acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart.”