"The default kernel runs Python code. The notebook provides a simple way for users to pick which of these kernels is used for a given notebook. \n",
"\n",
"Each of these kernels communicate with the notebook web application and web browser using a JSON over ZeroMQ/WebSockets message protocol that is described [here](http://ipython.org/ipython-doc/dev/development/messaging.html). Most users don't need to know about these details, but it helps to understand that \"kernels run code.\""
"Each of these kernels communicate with the notebook web application and web browser using a JSON over ZeroMQ/WebSockets message protocol that is described [here](https://jupyter-client.readthedocs.io/en/latest/messaging.html#messaging). Most users don't need to know about these details, but it helps to understand that \"kernels run code.\""