Magento uses the following types of libraries:
Magento PHP libraries, which are discussed in the next section
Magento UI libraries, which are located in the lib/web directory
Third-party libraries are organized by vendor to be PSR-0 compliant.
Magento PHP libraries
Magento PHP libraries include independent libraries of code useful to a Magento application. Each library has minimal dependencies on other library.
Magento\Framework\App is a special PHP library that is aware of Magento as an application. It represents a greater level of abstraction and provides the following:
Other Magento libraries do not reference