Notebooks are composed of paragraphs. Each paragraph has two sections: the editor section and the output section. The editor section can contain text and code, while the output section contains the results after the whole notebook or a paragraph has been run.
Text and code can be freely added to the editor section. Teragrep will automatically highlight your code if you add an interpreter at the start of your code, i.e.
%md with markdown text. Read more about interpreters here.
Notebook owners and writers can add new paragraphs in the notebook. By hovering your cursor above an existing paragraph and pressing the appearing 'add paragraph' button you can create a new paragraph.