Hi there, @jbevoffice.
QuickBooks Desktop (QBDT) and QuickBooks Online (QBO) can’t run simultaneously with each other because of their difference in features and accessibility type. QBDT to run on a Windows-based or an Apple-based computer while QBO works on multiple operating system and multiple devices.
QBO is designed to have access anywhere as long as you have internet connection because this program is cloud-base and can update your data into your account in real-time. However, it is not designed to replace QBDT.
I can see this article can give you more details about the features for QBDT and QBO: https://quickbooks.intuit.com/products/.
Also, you’ll want to check this video tutorial in the future if you wanted to use QBO and import your file from QBDT: How To Export Your QuickBooks Desktop Company File and Import to QuickBooks Online.
Let me know if you have other concerns about these programs. I’d be glad to help. Have a great week!
