Hello and welcome!

I'm going to use an example or two because it'll make more sense.

From your port: This is an item. It's linked in {bitem:2063018} format so you can see all the details about this particular item. It's a static item.

Assignment #3  (E) Bradan's last day of summer reminds him that mysteries still abound in the world. #2060318 by Cupadraig~The Remote Country

From my port: This is a book-item, and the 'entries' within it can also be linked separately. When I use {entry:794832} I won't link the entire book, so I used {fentry:794832} for this example.

Machine  (18+) NaNo 2013 Prep and Manuscript #1957025 by Storm Machine

21: Plot Background from Machine 

The difference in the second example is that there are many entries within the book and this will direct you to a specific one, while the other way links specifically to anything in your portfolio. Please ask more questions if I can help make that clearer.