The first thing we should do is to give out a proper definition of what routing actually is.

To cut it simple, we can say that URL routing is the server-side feature that allows a web developer to handle HTTP requests pointing to URIs not mapping to physical files. Such a technique can be used for a number of different reasons, including these:

• Giving dynamic pages semantic, meaningful, and human-readable names in order to advantage readability and/or Search Engine Optimization (SEO)
• Renaming or moving one or more physical files within your project's folder tree without being forced to change their URLs
• Set up alias and redirects