Why was the Global Interpreter Lock (GIL) added in Python?

The Global Interpreter Lock (GIL) in Python was introduced to simplify memory management and ensure safety when working with objects in a multithreaded environment.

The main reason for the appearance of the GIL is that CPython (the standard implementation of Python) is not thread-safe by default. The GIL guarantees that only one thread executes Python bytecode at a time, preventing concurrent access to the interpreter's internal data structures and reducing the likelihood of errors related to concurrent access.

Although the GIL simplifies the implementation of the interpreter and memory management, it limits the efficiency of multithreaded execution of CPU-bound tasks, as threads cannot run in parallel on multiple processor cores. To bypass this limitation, multithreading or asynchronous programming are often used.