Ruby on Rails is a web framework that allows web designers and developers to implement dynamic, fully featured web applications.

Ruby on Rails (aka Rails) is a server-side web application framework written in Ruby. Rails is a model–view–controller (MVC) framework, providing default structures for a database, a web service, and web pages. It encourages and facilitates the use of web standards such as JSON or XML for data transfer, HTML, CSS and JavaScript for user interfacing.

More info:

https://rubyonrails.org