Routes refers to virtual paths like
/dashboard which doesn't exists in the system as a real folder and Chevereto map that request to PHP. By default Chevereto comes with a lot of routes and all of them are in the
Custom routes are useful if you want to add things like your own API or you want to change how the default
/image route works. With this system you don't need plugins at all and you can highly customize anything by adding routes or overriding the existing ones.
You can totally overwrite the default routes or add your own new routes safely. To do this simply do your work in the
app/routes/overrides folder. You will need to look around the default routes to get used to it.
Feel free to do anything you want in the
app/routes/overrides folder, your changes won't mess the default routes at all and you will keep your changes when you update the script.
Routes are a feature of G\ Library so you should check the G\ Library documentation for extended information about system routes.