CAPTCHA
Completely Automated Public Turing Test to Tell Computers and Humans Apart
A challenge that distinguishes humans from bots to limit automation abuse.
A CAPTCHA presents a challenge that is easy for a person yet hard for a script, helping separate human users from automated bots. It is commonly placed on login pages, registration forms, and comment fields to slow credential stuffing, spam, and brute force attempts. It is a rate limiting and abuse control rather than an authentication factor, since it confirms a human is present but not which human. Accessibility and machine vision advances steadily weaken older image based versions.
Looking CAPTCHA up is step one. Getting tested on it is step two.
A free account opens all 4 Domain 1 objectives, 271 exam-style questions with a lesson and a lab on each, a placement check that skips what you already know, and a dated plan. No card.
Not affiliated with or endorsed by CompTIA.