In general, website URLs should be simple and human readable or 'friendly'. This aids in human recognition of the page in the address bar, makes manually typing a page easier, as well as providing more context around the page to Search Engines.
You should aim to use short human readable URLs, with words separated by hyphens, and remove file names, special characters, code strings and multiple levels of sub-folders. Most modern CMS systems will provide options to create friendly URLs. In some systems where a website is older or a collection of files this may be more challenging to reconfigure, but can still be achieved.