captcha

CAPTCHA (stands for ‘Completely Automated Public Turing test to tell Computers and Humans Apart’) is a Turing test to prevent website abuse. That’s an automatically generated testeasy to solve for a human being, but impossible (or hard enough) to resolve by computer:

The benefit of having CAPTCHA is obvious, as it is used to protect the site from bots, spam, flood, hacking accounts, fraud registration, fake entries, and so on.

Usually CAPTCHA appears as a distorted inscription of letters or/and numbers. They might be written with different colors, deformations, using extra lines, or random shapes. User should read this inscription and enter that to the specified field.

In order to have CAPTCHA in the own site you should either use inbuilt options of the engine (as in Joomla, for example), or some extra coding (as in Website templates), or 3rd party extensions (as in WordPress).