The Slim Framework is a PHP framework that distinguishes itself from its peers by taking a rather minimalistic approach. While broad-purpose back-end frameworks such as Laravel or Symfony come with a large load of pre-built tools, Slim is meant to only facilitate your end-users communication with your business logic and therefore motivates building tailor-made solutions that fit your specific business model perfectly.
Slim provides several components regarding common concerns, like security (CSRF protection is a big one), caching, and even flashing messages. In addition, it eases the integration of third-party libraries such as tools for working with databases (ORMs). However, none of these tools is included by default and has to be explicitly requested by your programmers ensuring the use on an ‘as and when needed’ basis leaving your application bloat-free.