Phusion Passenger v. WEBrick

Question

What is the difference between using Phusion Passenger or just using WEBrick (e.g., rails s) in terms of a production environment?

I understand that Phusion Passenger installs a module on either Apache or Nginx, but is it a full fledged ruby server? Is it just forwarding traffic back to a WEBrick instance?

If Passenger is just forwarding traffic, back to any ruby server, why not just use rvmsudo rails server -d -p80?

Answer 1

Phusion Passenger is a full fledged rails server. When it is used WEBrick is not involved.

WEBrick is just a reference web server to be used temporarily until you set up a production level web server. It is not particularly optimized. It is intended for you to find a better web server for production.