The templates section is where all messages that are sent as part of a notification are stored. 

There are various templates for the customisation of communications across various channels - eg: SMS, Email, In-App, Push and for numerous tasks like article alerts, password changes and signup.

These messages can be edited by pressing

To turn off a Notification Template follow this article

Simply type your message and edit your font. To be able to merge information in that is stored in the system use the merge fields by typing @, a box will appear with all the fields that you can pick from for that particular template. 

In order to see how the Merge Fields work see the below template and the email that has then been generated as a notification from this template. 

Not sure when a notification is triggered or who gets it? See this article