CAPTCHA kya hai?

1.  Text-based CAPTCHA: Aapko kuch distorted ya garbled characters dikhaye jaate hain jinhe aapko manually enter karna hota hai.
2.  Image-based CAPTCHA: Aapko kuch images dikhaye jaate hain jinme se specific objects ya patterns ko identify karke select karna hota hai.
3.  Checkbox CAPTCHA: Aapko ek checkbox ko check karna hota hai jisme likha hota hai "I am not a robot." Kabhi-kabhi iske saath additional challenges bhi hote hain.
4.  ReCAPTCHA: Developed by Google, ye CAPTCHA hai jo users ko verify karta hai aur sath hi sath digitizing books aur improving machine learning algorithms mein bhi madad karta hai.

CAPTCHA, jiska full form hai "Completely Automated Public Turing test to tell Computers and Humans Apart," ek security mechanism hai jo website forms aur online services mein use hota hai. Iska main goal hai differentiate karna between genuine users (humans) aur automated programs ya bots ke beech.

Jab aap kisi online form mein information submit karte hain, aapko kuch characters ya images dikhaye jaate hain jo aksar distorted hote hain. Aapko ye characters correct taur par enter karna hota hai takay system verify kar sake ki aap ek real human user hain, na ki koi automated bot.

CAPTCHA ke kuch common types hain:

1. Text-based CAPTCHA: Aapko kuch distorted ya garbled characters dikhaye jaate hain jinhe aapko manually enter karna hota hai.
2. Image-based CAPTCHA: Aapko kuch images dikhaye jaate hain jinme se specific objects ya patterns ko identify karke select karna hota hai.
3. Checkbox CAPTCHA: Aapko ek checkbox ko check karna hota hai jisme likha hota hai "I am not a robot." Kabhi-kabhi iske saath additional challenges bhi hote hain.
4. ReCAPTCHA: Developed by Google, ye CAPTCHA hai jo users ko verify karta hai aur sath hi sath digitizing books aur improving machine learning algorithms mein bhi madad karta hai.

CAPTCHA ke istemal se spam, unauthorized access, aur automated attacks se bachaya ja sakta hai, lekin kuch cases mein users ko bhi additional steps complete karne padte hain, jisse user experience thoda complex ho sakta hai.