The Uniform Resource Locator (URL) is a defined address that points to the position of a file on a Server and retrieves it. URLs are entered into a web browser to access documents on the web or are embedded as hyperlinks within a document. A Permalink can be used to make a URL permanently available.
This results in the following URL structure:
http:// www.domainname.de/ directory1/ file1.html
URLs are important factors for OnPage optimization. They reflect the page architecture of a web page. Once the URL structure has been defined, it should not be changed. It is advisable to think about URL structure in the website in advance. Once the search engines index the URLs, they should remain consistent and should not be modified. If a URL is altered, the search engine interprets the changed URL as a new address. This is how Duplicate Content can be produced. However, in order for search engines to read the URL, they must be readable by them. Special Characters should therefore be “translated” into ASCII characters.
Search engines place particular importance on speaking URLs (or “clean URLs”). Talking terms are used in a URL instead of cryptic parameters. Talking file names are easy to understand for web page users. Search terms are also used for Usability reasons in a URLs.
Google recommends webmasters use important and relevant search terms in a URL. If matching keywords are included, a search engine bot can more easily identify what content is on this page. Should Google implement the case sensitive search in the future, Case Sensitivity could become more important.