Sinatra is a DSL (Domain Specific Language), which makes it conceptually very similar to a framework, but to be more concise, as DSL is a language which has been configured and contrained to solve a particular problem. In this case, the base language is Ruby, and the problem it revolves around basic HTTP routing.

Sinatra is less like a framework in regards to it’s footprint, as it does not come preloaded with any assumptions about how you want to interact with a database, and there is no MVC (Model-View-Controller) architecture in place. Sinatra is a great tool for developing API’s because both are heavily concerned with actions based off of defined and directed HTTP calls.