In an ideal world, the Google would be able to find and understand all content anywhere on the web and return relevant results for your search regardless of technical considerations. The web is a technical platform, however, and there are correct and incorrect ways of developing websites. Certain kinds of issue can your website invisible to the Google search engines, making it less likely to rank well and provide a great user experience or follow proper google guidelines.

Common user can easily perceive, understand, navigate, and interact with your website. It is not only important from users perspective but from search engine point of view as Google

While some of these issues are caused by errors or mistakes which should clearly be avoided, others arise from simply choosing certain ways of presenting content that would not necessarily be “incorrect” in a strict web development sense.

In order to be an effective SEO, it’s critically important that you understand how search engines discover, understand and rank web pages from a technical perspective. This will help you with diagnosing inevitable problems, improving existing websites and specifying high performance redesigns or fresh builds.

Common problems resulting from this issue are:

• Poor indexation
• Duplicate content
• Problem with seo friendly url

You need to fix and prevent duplicate content issues within your site.  Google Search engines get confused about which version of a page to index and rank if the same content appears on multiple pages. Ideally, you should only have one URL for one piece of content. When you have duplicated pages, search engines pick the version they think is best and filter out all the rest. You lose out on having more of your content ranked, and also risk having "thin or duplicated" content, something Google's Panda algorithm penalizes

The fundamentals of technical SEO are powerful and can have a big impact on your bottom line. Don't ignore them and make sure you consult a search expert.