PyTorch is an open-source deep learning framework developed by Facebook's AI Research lab, designed for building and training neural networks. It provides a flexible and intuitive interface for defining complex models using Python, enabling dynamic computational graphs that allow for on-the-fly model adjustments. PyTorch supports a wide range of machine learning tasks, including natural language processing, computer vision, and reinforcement learning. Its seamless integration with Python’s ecosystem and extensive support for GPU acceleration make it highly efficient for research and production. PyTorch's rich library of pre-trained models and robust community support facilitate rapid development and deployment of AI applications. By offering both ease of use and powerful capabilities, PyTorch empowers researchers and developers to innovate and scale machine learning projects effectively.