What does this instruction in the Bundler setup mean?

I'm trying to setup Bundler w开发者_如何转开发ith Rails 2.3.10 to make the transition to Rails 3 easier. But I'm not sure what the instruction on this page means. Am I supposed to require all the gems that I'm using in my app? If so, where? Thanks for reading.

Use the Rails 2.3 tutorial http://gembundler.com/rails23.html it's better on your case.

The setup made all requirement of all gem in your Gemfile. He avoid to do a lot of require ''.