What is an ABI

This article provides a clear, beginner-friendly explanation of the Application Binary Interface (ABI). It starts by defining interfaces in general, then distinguishes between User Interfaces (UI), Application Programming Interfaces (API), and ABIs. The author explains that while APIs are interfaces for code written by developers, ABIs operate at a lower level, governing how compiled binary code interacts with other compiled code during runtime. The article uses Swift and iOS as examples to illustrate the compilation process and the need for ABIs. It emphasizes understanding over memorization and is part of a series teaching programming and data topics from fundamentals.