Ruby on Rails (often referred to as RoR or simply Rails) is an open-source web application framework written in Ruby. It was created in 2005 by David Heinemeier Hansson and is used by many of the world’s leading web applications, such as Airbnb, GitHub, and Shopify. Rails utilizes the Model-View-Controller (MVC) architecture pattern to separate business logic from presentation logic. This allows developers to quickly create complex applications with minimal code. With Rails, developers can use a variety of templating systems and databases, making it highly versatile.