Completely Automated Public Turing Test to Tell Computers and Humans Apart (CAPTCHA)
Completely Automated Public Turing Test to Tell Computers and Humans Apart (CAPTCHA)
- April 27, 2021
- Posted by: Nicola Selenu

Completely Automated Public Turing Test to Tell Computers and Humans Apart is more commonly referred to by its acronym, CAPTCHA.
It is a type of challenge-response test used in computing to determine whether a user is a human or a machine. Websites use CAPTCHA to prevent spam and automated extraction of data. Because computers are unable to distinguish letters and numbers within moving or distorted images, CAPTCHA typically requires a user to enter letters or numbers presented in a visually distorted field. It is also common to choose from a variety of images where you need to select a common theme.
Author:Nicola Selenu
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Completely Automated Public Turing Test to Tell Computers and Humans Apart (CAPTCHA)
Completely Automated Public Turing Test to Tell Computers and Humans Apart (CAPTCHA)
- April 27, 2021
- Posted by: Nicola Selenu


Completely Automated Public Turing Test to Tell Computers and Humans Apart is more commonly referred to by its acronym, CAPTCHA.
It is a type of challenge-response test used in computing to determine whether a user is a human or a machine. Websites use CAPTCHA to prevent spam and automated extraction of data. Because computers are unable to distinguish letters and numbers within moving or distorted images, CAPTCHA typically requires a user to enter letters or numbers presented in a visually distorted field. It is also common to choose from a variety of images where you need to select a common theme.
Author:Nicola Selenu
Email Service Providers Handbook
The most comprehensive “Handbook of Email Service Providers“!
SPAMASSASSIN RULES
All SpamAssassin rules in one place, EXPLAINED!
SMTP COMMANDS
& REPLY CODES
All SMTP/ESMTP commands and reply codes in one place, EXPLAINED!
Free DNS Tool
Check the DNS records of your domain with our free DNS tool.
Deliverability Glossary
The most comprehensive Email Deliverability and Marketing Glossary!
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