What is the fundamental difference between a framework and a library in software development?

The fundamental difference between a framework and a library lies in the control over the program's flow:

• Library — is a set of ready-made functions and classes that the developer calls at their discretion. Control remains with the calling code.

• Framework — is the application skeleton that defines the structure and flow of execution. The developer inserts their code into specific points, and the framework calls this code. This is called "Inversion of Control".

Example:

• A JSON library provides parsing functions that you call when needed.
• A framework, such as Spring in Java, manages the application's lifecycle and calls your components at the appropriate times.

Thus, the framework sets the architecture and manages the process, while the library simply provides tools.