Difference between npm run watch and npm run watch-poll
watch
will listen for file changes, however, on certain systems this won't always work.
watch-poll
periodically checks (polls) for changes e.g. every 1000ms it will manually check to see if any files have changed.
https://laravel.com/docs/5.4/mix#running-mix
https://webpack.js.org/configuration/watch/
watch-poll
is an alternative to watch
in certain enviroments watch
might not track changes properly, therefore watch-poll
was implemented.
Poll will check the files every x seconds rather than automatically picking up on changes through watching.
You can read up on the docs for a more information about mix.