The best resource is right here : https://laravel.com/docs/5.8/routing#named-routes
One of the common use case is in your views. Say your post request goes to a particular route, basically without named routes you can simply go like this to store a task
but say for example you need to update the route to /task/store , you will need to update it everywhere you use the route.
But consider you used a named route
With named routes you can use the route like this in your view:
Now if you choose to update your route, you only need to make the change in the routes file and update it to whatever you need.
If you need to pass arguments to your routes, you pass it as arguments to route helper like this:
route('task.edit', 1), // in resource specific example it will output /task/1/edit
All of the view examples are given you use blade templating.