Python libraries are collections of modules and functions that extend the language's capabilities. Some popular Python libraries include:
- NumPy (numerical computing)
 - pandas (data manipulation)
 - Matplotlib (data visualization)
 - scikit-learn (machine learning)
 - requests (HTTP requests)
 - BeautifulSoup (HTML parsing)
 - Django and Flask (web frameworks)
 - TensorFlow and PyTorch (deep learning frameworks