Annotations

What is the Definition of an Annotation? 

• to make or furnish critical or explanatory notes or comment; to make or furnish annotations for (something, such as a literary work or subject); a note added by way of comment or explanation (Merriam-Webster)
• to add notes or remarks on a piece of writing (Cambridge Dictionary)
• Annotating is any action that deliberately interacts with a text to enhance the reader's understanding of, recall of, and reaction to the text. (Writers' Center)

Annotating a source