+ 4
In simple words:
Ruby is the programming language,
Rails is the web development framework written in ruby.
Detailed technical info below:
Ruby?
https://www.ruby-lang.org/en/about/
https://en.m.wikipedia.org/wiki/Ruby_(programming_language)
Rails?
https://railsapps.github.io/what-is-ruby-rails.html
https://en.m.wikipedia.org/wiki/Ruby_on_Rails