There are different ways of showing your site content on the Internet. Many site applications show pages in format similar to this:
http://yourdomainname.com/index.php?page=photos
Such links are bad for the SEO of your website. The search engine will consider bothhttp://yourdomainname.com/index.php and http://yourdomainname.com/index.php?page=photos as one page despite the fact that those URLs display different content. This will generate errors with duplicated meta content, duplicated titles and more.
This is why you should set up your application to use Search Engine Friendly (SEF) URLs. Below you can see two examples of SEF URLs:
http://yourdomainname.com/photos
http://yourdomainname.com/contact
Such links will be "crawled" by the search bots correctly and indexed in the Search Engine Result Pages (SERP).
If you want to rank high in SERPs, you should definitely set your links to be Search Engine Friendly.
Another benefit you get from using SEF links is that your visitors will remember the links to different parts of your website more easily. In terms of usability, having SEF URLS is a must.
