C extensions in Python are a powerful way to enhance the performance of Python applications by integrating C code. This approach allows developers to bypass Python’s Global Interpreter Lock (GIL), enabling concurrent execution and efficient handling of computationally intensive tasks. By writing critical parts of the code in C, developers can achieve significant speed improvements, particularly in areas like numerical computations and data processing. C extensions also facilitate direct interaction with C libraries, making it easier to leverage existing C codebases. Overall, they provide a bridge between Python’s ease of use and C’s performance capabilities.