Cloaking is bad technique to do SEO for top rankings in search engines. Search engines like Google may ban or blacklist your website due to cloaking.
Cloaking is black hat SEO technique in which content presented to search engines is different from content presented to user’s browsers. In cloaking, a programmer write a code for search engine’s purpose like when search engines visits a page, inserts some keywords and content for search engine only while general users will see some banner or images etc. – a different content.
Google algorithm is smart enough to find cloaking in websites so never try to be smart otherwise Google penalty can make your website rankings down or Google will de-index and ban your website.
New SEO’s who don’t know about cloaking, need not worry because they are not doing cloaking. In Google guidelines it’s clear that if any website found to be use black hat seo or cloaking, the website will be ban permanently or temporarily.
There is also while hat cloaking, it is without penalty or ban. Like, if you are logged in Google account and if you search something then you will find a different results while if you search in different browser without Google login, you will find different results. It’s due to Google cache while you searched previously.
Another example is for any website like- when you direct visit any website, first you will see a banner ads on home screen and after skipping that ad you will reach to home page but in case of search engines, it never shows them ad content on home page visit. Means website shows different view to robots and users. But it does not comes in under penalty.
Matt Cutts explains cloaking –
SEO cloaking Checker – Some online tools to check cloaking in any website, it detects whether any website using “cloaking,” a server side technique try to fool the search engines for better rankings the Web pages do not deserve. Cloaking involves showing one version of a Web page to users and a different version, usually stuffed with other keywords, to the search engine spiders. These tools help to find cloaking –
I personally highly discouraged to use cloaking. Comments are welcome for more discussions on cloaking, its very wide topic. Thanks.