When you start off with Rails there are a few things that take a bit of getting up-to-speed with.
Here’s a list with explanations:
1. Rails is built on Ruby
Ruby, currently version 2.0.0, is a language built by Yukihiro Matsumoto, a Japanese computer scientist and software programmer. He’s popularly known as Matz.
In creating Ruby, he blended parts of his favourite languages (Perl, Smalltalk, Eiffel, Ada and Lisp) . He also created its reference implementation, the MRI (Matz’ Ruby Interpreter).
Ruby balances functional (computation as the evaluation of mathematical functions) with imperative (emphasises change in state) programming.
2. Rails is a Ruby gem
A RubyGem is a software package (aka a “gem”). A gem contains a packaged Ruby application or library.
Each gem has a name (e.g. “rails”), version (e.g. “4.0.0”) and platform (e.g. “ruby” or “java” or “mswin32”).
Gems contain 3 components: code (including tests and utilities), documentation, gem spec
3. You’ll most likely install Ruby using rvm
rvm is short for Ruby Version Manager.
4. You’ll use bundle to maintain a consistent environment for your ruby applications.
It tracks your code and gems so that an application will always have the exact gems and versions it needs to run.
bundle is a command that’s provided by the bundler gem. You’ll install it using:
gem install bundler
A file, the Gemfile, is used to maintain these dependencies.
When you use bundle install to install all dependencies another file is generated called Gemfile.lock. This lists all your gems with their versions and dependencies.
A very useful guide to installing Rails on a Mac: