I am still very new to web development so sorry if the answer is obvious!

Anyway, I have created a form for my website that lets users email me a request. I'm using `nodemailer` to do this in my `app.js` script. Also using `Express`, obviously. Anywho, during testing when I run the local server `'node app.js'` everything works fine, ie. I open up my `index.html` on `localhost:3000` and can successfully send myself an email through my form. Now I just have to add all the files to my website's cpanel public\_html folder. AKA make it official.

THE QUESTION: Is `app.listen(*port number*)` necessary at all when I put `'app.js'` into my website's files? Will my `index.html` form still activate `'app.js'`, as long as it's available?

Again, still very new to this, at least the back-end stuff. Thank you for any help.