How to quickly tell what a URL maps to? I'm in a new position working on an existing Drupal 7 site that I didn't help build. None of the original devs are here. Amongst other modules, the site makes uses of panels, panelizer, aliases, and redirects.

I get requests from marketing to update or change a page, and they include a URL. The URL is often an alias, but sometimes it can be a panels page, or a drupal entity "overriden" by panelizer. 

Is there an easy way to see what exactly a URL maps to when I get a URL from marketing?
There is no easy way. You have to have deep knowledge of the site's content to know how to edit what appears on the page. This is only obtained through poking around the site or asking a knowledgeable colleague.