"On-Rails" refers to a design pattern commonly used in software development, particularly in web applications. It allows developers to create applications that follow a specific structure and set of conventions, making it easier to build and maintain code. This approach is often associated with the Ruby on Rails framework, which emphasizes convention over configuration. In the context of web development, "On-Rails" helps streamline the process by providing built-in tools and libraries. This means developers can focus on writing the unique features of their application rather than dealing with repetitive tasks. Overall, it promotes efficiency and consistency in coding practices.