What is GIL in Python?

GIL (Global Interpreter Lock) is a mutex that protects access to Python objects, allowing only one thread to execute Python code in a process. Present in the CPython implementation, it simplifies memory management but limits performance in multithreaded programs on multicore systems. For true parallelism, you can use multiple processes (multiprocessing), alternative implementations such as Jython or IronPython (without GIL), or C extensions that free the GIL during intensive operations.