What is a jupyter notebook?

Answer 1

It's an Integrated Development environment for Python. It has to be uploaded to a local host for use

Answer 2

You can read about it here:
http://jupyter.org/

Answer 3

okay.. thank you

Answer 4

It can be viewed as an "executable" document, a document in which you can include code (Python, Julia or Erlang: Ju Pyt Er) snippets. When you select a snippet, you can run it and the output is inserted into the document. The output can be a Youtube video, an image, the result of an algorithm, a graph drawn by matplotlib, html formatted text. This makes jupyter notebooks an excellent tool for tutorials or sharing research findings. You even can edit the code and execute the modified version.