Ruby apps are web applications built using the Ruby programming language, often with the Ruby on Rails framework. Ruby is known for its simplicity and productivity, making it a popular choice for startups and developers who want to build robust, scalable websites quickly. These apps can handle everything from e-commerce platforms to social networks and content management systems.

Key features of Ruby apps include:

• Convention over Configuration: Rails provides sensible defaults, reducing setup time.
• MVC Architecture: Separates code into Models, Views, and Controllers for better organization.
• Gems: Libraries that add functionality, like payment processing or authentication.
• Database Integration: Easily connects to databases like MySQL or PostgreSQL.

For hosting, Ruby apps typically require a server environment that supports Ruby and Rails, such as Passenger, Puma, or Unicorn. Many hosting providers offer specialized Ruby plans with pre-installed dependencies and tools like Bundler for managing gems. When deploying, ensure your hosting supports the required Ruby version and provides adequate resources for performance.

In summary, Ruby apps are efficient, developer-friendly solutions for dynamic web projects, and choosing the right hosting is crucial for their success.