Much like other frameworks (.NET, Zend, etc), RoR automates a lot of the repetitive tasks we are often faced with during the development process. RoR is built upon the Model View Controller design pattern. Also, RoR has a great implementation of the Active Record pattern. In a nutshell, the entire framework is OO, which lends itself to extensibility and reusability.
Take the time and watch this walk through-- [
media.nextangle.com]