@caftpx10 - You're "thinking in HTML". In server-side scripts, it's common to include from includes that are included by other includes (and so on, and so forth). At the end of the day, you don't know exactly where the code that is creating links is running (and especially
cannot be sure where you're running relative to the server root, as opposed to the application root); generating a server-relative link sort of depends on knowing where the asset you are linking to lives. Believe it or not, your average website owner doesn't know much about the applications they're running other than how to follow the setup and configuration instructions (maybe; there's often Softaculous and a support ticket or two involved in getting that far) and how to add stuff through the admin panel. Frankly, that's all they
should have to know; you wouldn't force a novelist to be able to modify and build a word processor or a cashier to build out a POS system to get their work done either. So the app may be living in any install directory, and those assets are usually in subdirectories of the install directory. The app should be able to figure out from its pages'/scripts' own locations how to navigate to its own assets. If it can figure out
__FILE__ and the current document root, it can point to anything it "knows" about, regardless of where the script is installed or how it's being accessed (as a potentially-deep subdirectory, an add-on domain, a subdomain, etc.).