Metadata just means "data about data"; think like, when you open a photo on your computer and it tells you the location it was taken, or the time/date, when you click details. That information isn't in the photo, it's encoded in the metadata. What I mean about creating metadata in Lists is that you can use the Notes feature to label or otherwise sort articles. For example, on an article titled "15 Cool Writing Prompts" you might note "number 7!" to remind yourself which one you wanted to keep track of. Or add any other note-to-self or notes-to-the-reader to help you/readers remember what the article was about. "Excellent sources," "Check out no. 8," "great resource," "check around Christmas," etc. You can even note what day you read it, or something like that. Hope that answers your question!