Good day, root20.
QuickBooks Desktop and QuickBooks Online both have their own advantages. QB Desktop needs to be downloaded to a computer and access locally. With QB Online, you can access your account online.
Here's a link for QuickBooks comparison: Comparing Quickbooks Online to the QuickBooks Desktop versions.
Check out this article for future reference: https://quickbooks.intuit.com/move-from-desktop-to-online/.
Let me know if you have additional questions.
If you have inventory type items, or classes in QBDT, those are not in essentials, only in the plus version
a non partisan comparison of QBO vs QB desktop http://onsale-apparel.com/Rustler/qbo-or-qbdt (cost comparisons are at the end of the article)