Python's REPL, which stands for Read-Eval-Print Loop, is an interactive programming environment that allows users to write and execute Python code in real-time. It reads the input code, evaluates it, and then prints the output, making it a useful tool for testing snippets of code quickly and experimenting with Python features. The REPL is particularly beneficial for beginners learning Python as it provides immediate feedback on their code. Users can enter commands one at a time, see results instantly, and make adjustments on the fly, enhancing the learning experience and facilitating rapid development and debugging.