CAPTCHA stands for Completely Automated Public Turing test to tell Computers and Humans Apart. Developed and trademarked by Carnegie Mellon University, the job of this test it to know if it’s a person or a computer trying to access your system or website. Read more about CAPTCHA at http://www.protectwebform.com/.
When you take the test that CAPTCHA gives you and give the right answer, it knows that you are a human. For instance, it will ask you to key in letters from a distorted image of alphabets and numbers. The machine will not be able to figure it out correctly. That makes it quite easy for CAPTCHA to know the difference. You can get further details from http://www.protectwebform.com/smartcaptcha.
Most website owners opt for a function wherein the visitors can send in their feedback without allowing spammers to barge in. The moment you post your email id on the net, you can rest assured of the attack from the spammers. Automated programs that are better known as bots have the ability to scan your website and parse out your mail id. The spammers use the email ids for many purposes without your knowledge or permission.
Another option is CAPTCHA that does not allow the spammers to get access to your email ids. Many websites and sign-up pages use CAPTHCA. It assumes that computer programs cannot read distorted characters. It is considered fairly reliable.
CAPTCHA can be said to be a program that has the capability to create tests which only humans can clear. The program is a fully automated program and no human intervention is required. Thus it is so much preferred by website owners. CAPTCHA has become very popular in the past few years.
The key to CAPTCHA is using it to stop spammers before they ever get access to your email. Once they have it, you have lost the game and they will be regularly sending you spam emails you don’t want.
In other words, CAPTCHA not only prevents encroachment by spammers for commercial purpose, it also protects the systems that are gullible to spam like, the webmail services of Gmail, Hotmail, and Yahoo. They also help prevent automated postings on online blogs. CAPTCHA helps in enforcing a usage policy and prevents any kind of deviation from the policy. This is required in case a service allows automated use but within a limit.
There are others out there that claim to do what CAPTCHA can do. They have created similar programs that ask varying questions to allow someone to get into a site or sign up for a blog. None of them are as reliable as CAPTCHA because with a database, any of the other programs questions could be answered, while the CAPTCHA image recognition system is foolproof.
