Ruby on Rails Server options

The whole issue of setting up a development server for my Ruby on Rails application confuses me. There are WEBrick, Mongrel, Passenger, Apache, Nginx and many more I am sure, and I don't really understand the different roles they play. I started off using WEBrick, and now I use Mongrel for development. Are these servers stand-alone, or do they sit in front of Apache? I have read about Passenger and I don't really understand what it is, the site says "makes deployment of Ruby web applications a breeze", does it replace Mongrel? Is it like Capistrano, which also deploys web applications? Bearing in mind I would like to test SSL, and I believe that's not supported by mongrel, what is the best development server setup? Thanks