Everything you need to know about Jupyter Notebook

To start a notebook 
In terminal, run

jupyter-notebook 

Now, the notebook will be opened in your default browser.

To change the current line as comment

Ctrl + /   (this will change the current line in to a comment. To convert multiple lines of code in to a comment, select the lines that you want to convert and then hit Ctrl + /

Running different programs in Jupyter-Notebook

You can run Bash comments in jupyter-notebook. In any cell, type %%bash then that shell can be used to to bash comments. Similarly, other programming languages also can be run. A detailed post will be written on this topic.