What is captcha and how does it works?

CAPTCHA is a security feature used on websites to check whether the user is a real human or a bot. You’ve probably seen tasks like selecting traffic lights, typing distorted letters, or clicking specific images before logging into a site. These tests are designed in a way that humans can solve easily but automated bots struggle with. Websites use CAPTCHA to reduce spam, fake account creation, hacking attempts, and unwanted automated activity. Modern CAPTCHA systems have become smarter and sometimes even analyze mouse movement or behavior patterns. Honestly, they can feel annoying sometimes, but they are one of the main reasons many websites stay protected from spam attacks.

The fullform of CAPTCHA is, "Completely Automated Public Turing test to tell Computers and Humans Apart." It is a type of security test commonly used on websites in order to determine whether or not the user submitting the form comes from a computer, or a person. There are two main types of captcha systems: text-based and image-based. Image-based captcha systems are typically easier to solve than text-based because they can't be solved with traditional word methods like look up, comparison, subtraction, listing, etc.

Text based captchas work best by using words that includes numbers or letters that can be computed with word method as previously mentioned.