CAPTCHA can protect applications from such abuse.
Protecting website registration – websites offering free services upon registration are often attacked by automated scripts that create thousands of accounts to obtain the free service or sell them.By using CAPTCHA, websites can block such unwanted actions. Spam software can send thousands of messages in a short time. Preventing spam on blogs and forums – spammers are always looking for places to send spam to promote some products, publish unwanted content, or rising ranks.Below we can see an example of such a CAPTCHA: The image is malformed in a way that only humans can correctly evaluate it and computer software should not. The most common type of CAPTCHA is a distorted image of text that users must correctly rewrite into a text field. The CAPTCHA is an algorithm preventing applications from bots and various spam attacks.
