In this chapter, we are going to talk about an exciting and important topic called Ruby gems. Gems are modules and classes that provide additional functionality to an application. Some gems provide so many features that individuals new to development may even think of them like some kind of programming magic. However, essentially, gems are nothing more than Ruby code files that perform certain tasks.
To give you an idea of how gems are used, I'm going to open Gemfile in a Rails project:
source 'https://rubygems.org'
gem 'rails', '~> 5.0', '>= 5.0.0.1'
gem 'pg', '~> 0.15'
gem 'sass-rails', '~> 5.0'
gem 'uglifier', '>= 1.3.0'
gem 'coffee-rails', '~> 4.1.0'
gem 'jquery-rails'
gem 'turbolinks'
gem &apos...
