Captcha
CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) is a security measure used online to differentiate between human users and automated bots. By presenting tasks that are simple for humans but challenging for machines, such as recognizing distorted text, identifying objects in images, or solving simple puzzles, CAPTCHAs protect websites from spam, automated account creation, and other malicious activities. While essential for internet security, CAPTCHAs balance between user-friendliness and robustness against evolving bot capabilities.