Rails enhances the flexibility of Ruby nicely. It allows built-in classes to seamlessly include extra fancy methods which sound like human language.The elegance and power of Rails is leveraged atop the malleability of the underlying Ruby language. Here's some proof:

kiffin@F5SL:...orial-hartl/sample_app $ rails console
Loading development environment (Rails 4.0.2)
>> 1.year.from_now
=> Sun, 21 Dec 2014 14:20:37 UTC +00:00
>> 10.weeks.ago
=> Sat, 12 Oct 2013 14:20:47 UTC +00:00
>> 1.kilobyte
=> 1024
>> 5.megabytes
=> 5242880

See Learn Web Development with Rails by Michael Hartl for a great introduction to Rails.