Do you see how moon has these surrounding it: ( ). Those are called parenthesis.
This should help you understand:
https://en.wikipedia.org/wiki/Parenthesis_(rhetoric).
Here's a little more info: > Parenthesis are a punctuation mark used to contain text that is not part of the main sentence, but that is too important to either leave out entirely or to put in a footnote or an end note.
Now, look at this example: A wild Pokemon (Pikachu) appeared. Pikachu has parenthesis around it to tell you which Pokemon is the one you found without interrupting the sentence. I'm no expert on this stuff but I'm using my knowledge and other sources (like wikipedia) to help.
