Ruby is a very high-level programming language created by Yukihiro Matsumoto in an effort to emphasize human needs instead of computer needs. A high level language is one that is closer to human languages and further from machine language (ones and zeros).
According to the creator of the language, Ruby was made to make programmers more productive and happy and that seems to be the case as the language is used by massive companies such as Twitter, AirBnb, Shopify, Stripe and Github. Most programming languages have similarities and because Ruby has the most readable syntax for new developers, it's a great language to learn as an introduction to programming as it can help to understand how other languages work.
Help and documentation for the Ruby programming language
The basics of programming in Ruby
Become a Ruby expert by learning from Jesus
A great introduction to Ruby by Codecademy
A book written by the author of the Ruby language
Free online guide book for learning Ruby