Their landing page of their site isn't too bad the first thing you see is The Jupyter Notebook is a web application that allows you to create and share document

Their landing page of their site isn't too bad the first thing you see is The Jupyter Notebook is a web application that allows you to create and share documents that contain live code, equations, visualizations and explanatory text. Uses include: data cleaning and transformation, numerical simulation, statistical modeling, machine learning and much more. Though I am not sure why their blog doesn't link to the landing page of the site.