What is Rails

Rails is a software library that extends the Ruby programming language. It's code that is added to Ruby. Technically, it is a package library (called, a RubyGem), that is installed using the command-line.

Rails is a framework for building websites quickly and efficiently. As such, Rails establishes conventions for easier collaboration and maintenance. These conventions are organized in the Rails API. Learning Rails means learning how to use the Rails conventions and its API.

Rails combines the Ruby programming language with HTML, CSS, and JavaScript to create a web application that runs on a web server. Because it runs on a web server, Rails is considered a server-side, or “back end,” web application development platform (the web browser is the “front end”).

Rails is popular among web startups, significantly because the pool of open source software libraries (“gems”) makes it possible to build complex sites quickly.