Hi there,
First thanks for your interest in the library! In short, StanfordNLP library (as of v0.1.1) is a combination of the two: an independent Python NLP pipeline and a Python interface of the CoreNLP server. Details below:
1. Independent Python NLP pipeline: an important part of this new library is a deep learning-based NLP pipeline which is built from the ground up in Python, by using the PyTorch framework. This pipeline currently supports tokenization, sentence split, lemmatization, pos and morphological features tagging and universal dependency parsing. There are three main advantages of having this pipeline: 1) it provides native Python implementations, which is currently the main language of a lot of NLP researchers/practitioners; 2) by using deep learning models, it now supports 53 human languages with a single model architecture; 3) the deep learning components can also provide very accurate and even state-of-the-art results on many languages (as measured in the UD shared task). Note that currently this Python NLP pipeline is completely independent from CoreNLP, and you can refer to this page in order to use it:
https://stanfordnlp.github.io/stanfordnlp/installation_download.html
2. A Python interface of the CoreNLP Java library: this part of the library is dedicated to communicating users' requests with the backend CoreNLP server, and converting the results returned by CoreNLP into local Python objects. The advantage of having this interface is obvious: while the deep learning-based Python NLP pipeline provides support for many more languages, it currently lacks many functionalities that CoreNLP provides (e.g., high level tasks such as named entity recognition, relation extraction, etc.). Therefore having this Python interface will help unlock these possibilities. For instructions on how to use this interface, please refer to this page:
https://stanfordnlp.github.io/stanfordnlp/corenlp_client.html
I hope these will answer your question?