Ruby is a dynamic, open-source programming language known for its simplicity and productivity. It emphasizes an elegant syntax that is easy to read and write, making it a popular choice for beginners and experienced developers alike. Ruby is often used for web development, particularly with the Ruby on Rails framework, which streamlines the process of building robust web applications. A gem in the context of Ruby refers to a packaged library or application that extends the functionality of the language. Gems can be easily shared and installed using the RubyGems package manager, allowing developers to leverage existing code and tools to enhance their projects. This modular approach fosters a vibrant community and encourages collaboration among developers.