Each chapter is comprised of different kinds of content - called blocks. These blocks can be reordered and stacked to form the structure of the chapter.
To access them, you'll have to be in the node editor view. This is what you see when editing a node.
The node editor is where you'll spend most of your time, because it's in this editor that you'll input all the text and configurations of the nodes. Below is a screenshot of the editor with the correspondent legend.
Save and keep the node editor open;
Save and close the node editor;
Close without saving;
The node ID;
Details of the node's relationships: what is/are the previous node/s ("From") and what is/are the next node/s ("To") - this means from what nodes there was a jump to this node, and to what nodes will the story goes from here;
The title of the node/chapter;
An URL for the main image of the node/chapter;
Where the content for this node will be displayed;
The several options for the types of content that can be included - the blocks.