libBGPStream is the core of the BGPStream framework; all tools, as well as the Python bindings use libBGPStream. libBGPStream is written in C, making it very efficient. The API has also been designed to be as simple as possible.
PyBGPStream is our Python bindings to the libBGPStream C API. It offers the same functionality (and much of the same efficiency) as the C API, but also the flexibility of a Python module, allowing rapid prototyping and integration.