URL Structure is an important part of search engine optimisation. Namely because URL structure helps dictate keyword usage within the URL name. URL Structure is typically setup depending on the websites server technology, and depending on the websites structure. Friendly structures operate in a hierachy which seperate different website pages, typically by theme. A good URL structure will seperate products, information, themes and so forth.
URL Structures are either based on URL rewriting, or by raw assignment, which will mean the page extension is shown.
Example:
URL Rewriting Disabled:
www.mysite.com/myproduct/page1.html
URL Rewriting Enabled:
www.mysite.com/myproduct/product1
Search engine optimisation is aided by keyword usage within URL's. Typically, keyword usage in URL's can compensate for domains that do not use the keyword within. When keywords are used in URL's they should be implemented in a proper manner, avoiding excessively long URL's. The website structure should also be broken down based on the subjects and themes covered,
For Example:
www.mywebsite.com/theme/page-on-theme
So, the theme can for example, cars, and the page could be about Vauxhall, this principle should apply site wide to separate information. This system helps to prevent supplemental results, mixed themes and other website issues.
A good foundation for a website will rely on its ability to separate information through a URL hierarchy, generally, a website will break information up into categories. Combining this with optimal keyword usage will help boost the rankings for the website.
Keywords within URL's should be selective based upon their most direct values, for example, if the URL is to discuss food, the top level keyword should be based on food instead of multiple keywords, this helps keep the URL within compliance length.
Ideally URL length should remain below 250 characters, URL's exceeding this length can become truncated, or can appear spam like.