What is Image Verification ( Captcha )?

A security test to determine whether or not the user is human. This will ensure that only human visitors will actually submit the form, and not one of the spamming 'bots' that constantly browse the web from site to site, submitting spam where they can. It is well known that programmers can create programs for many purposes, including visiting sites on the Internet by following links from page to page, collecting emails listed on websites, submitting contact forms, or even trying to break passwords by trying to login over and over again with computer generated passwords.

Fortunately, it is extremely difficult, if not impossible, for a non-human ( eg. computer program ) to extract a word or a combination of letters and numbers from an image if the letters and numbers are not all of the same size and of similar font. This is how the Image Verification security method can ensure that only real people can actually submit a form.