It can also be used to create different Namespaces that can hold templates and variables that can be used across all lessons within a project.
Any templates or variables that are created under the Lesson namespace will only be available in that specific lesson. In order to create variables and templates that can be used in all the lesson in the project, you need to create a new namespace.
To create a new namespace right-click on the Lesson namespace in the Namespace tab and select add -> Namespace. Give it a name and it will be added to the Namespaces tab.
Right-click on the new namespace and you can add a new variable or template. Now when you start a new lesson this namespace and all its associated variables and templates will be available in the Namespaces tab.
Every namespace is saved as a seperate entity in your project folder as a .mtclass file. This file can be imported into other projects, it also allows for easier project collaboration. In the Portal, when you are syncing your changes you can add or update these .mtclass files individually.