• When your content is found on other web pages with the same or almost the same content.
• Duplicate content does not occur only on different websites, but on a single website as well.
• It is possible that web pages are considered duplicate even if they are not 100% identical.
• In an attempt to curb the garbage in search engines, only one version of duplicate contents may be listed. This is because search engines want to list as many available options as possible and filtering all duplicates is necessary.

Two easy ways to avoid duplicate content in your websites

1.    Hide them from search engines.

a.    You could be facing problems if your website is offering different flavors of content, such as regular view, mobile view, print view, and others. The search engine might pick the wrong version for the search results.

b.    Adding a noindex meta tag instructs the search engines not to index duplicate content.  There are utilities that can accomplish this job easily.

2.    If you are syndicating your content, DO REQUIRE back links.

a.    Syndication is popular these days and if you are doing this, search engines might prefer the one being published by your partners.

b.    Adding a back link towards the original document on your website can solve this dilemma because the search engines can now peek from the page where the content comes from.

It is established that duplicate content can and will cause problems with your rankings. Follow the simple tips above, and you will have no problems with the search spiders. Also, it is important to optimize your site for these little spiders, and one way is to optimize your internal link structure.