Question: I'm a noob to RoR, so any help/clarification is appreciated.

Is the .gitignore file in Rails universal/global to all of Rails, or does each project/app have its own .gitignore?

Answer: 
`.gitignore` is a Git file, it has nothing to do with Rails.

A `.gitignore` file will apply to the directory it is in and any subdirectories. You can create `.gitignore` files in subdirectories to have them only apply to those subdirectories and their descendants.
There's a .gitignore\_global file in your ~/ directory that every git instance references.
Git is independent of rails.
the .gitignore file is restricted to the initialized repository.