Ruby is the name of a popular programming language. Started by 1993 by Yukihiro Matzomoto in Japan, Ruby is an English-like language that's great for beginners but also used for large scale, industrial-strength applications. The language continues to improve and evolve over time. The current version of Ruby is 2.4. Ruby is used behind the scenes to power large websites and web applications like Basecamp, Hulu, Amazon, Kickstarter, YellowPages.net, and more. However, Ruby is different from HTML.
Unlike HTML which provides instructions for the browser, Ruby provides instructions directly to a computer. Ruby programs can perform computation, modify documents, communicate with other computers, give you directions to the ballgame, check the weather outside, and more.
Ruby instructions can only be understood by the Ruby interpreter, which must be activated from your computer's command prompt. If you aren't familiar with the command prompt, stop now and spend the next ten minutes learning the command prompt.