Always use SEO-friendly URLs for your websites. If you use keywords in your URLs then your website will show up in a higher position in search results.
By doing this you are increasing the number of quality back links to your website, a factor that search engine bots take into account when ranking your website on search result pages.
The basic idea is that it is a way to cause your website to appear higher on the list after a general search is done for a specific string of terms or words.