Ruby on Rails is a web application framework that allows developers to build dynamic web applications using the Ruby programming language. It emphasizes convention over configuration and aims to increase developer productivity. Some key features of Rails include its use of the MVC framework, Active Record for database access, scaffolding for quickly building CRUD applications, and support for metaprogramming techniques. Rails also supports test-driven development and provides environments for development, testing and production.

1. Ruby on Rails ::The New Gem of Web Development

9. b = Post.find(:all, :conditions => ['score > 80']) is conceptually equivalent to the following SQL command: SELECT * FROM posts WHERE score > 80;

14. Its just like this

15. Thank you