What is Captcha?
Captcha entry is a method by which you have to write the characters shown in a jumbled manner or in upper and lower case correctly to login the site and same is visible to the users who are showing an abnormal activity while accessing the website. The Wikipedia states it as a type of challenge-response test used in computing as an attempt to ensure that the response is generated by a person. You may also find it if you enter login password wrong a number of times like in email or blogger services.
How Captcha Helps Prevent Spam?
Typing the characters in the picture shown in the captcha helps to ensure that a person, not a program, is performing a search or accessing the website.
How Captcha Works?
The below is a screenshot of Bing Search engine Captcha exercise which will show how captcha works.
Why Catcha is Important?
Captcha is important due to following reasons on the search engines:
Some programs perform repeated searches for malicious purposes. Preventing those automated searches ensures that everyone else has faster, more reliable search results.
You may see the captcha if your computer, or another one in your network, has done so much searching lately that the original website was concerned and an automated program might be activated.