@Green roof plants  They are only discontinuing sales of QuickBooks Desktop for new customers, not existing customers. You're basically grandfathered in for now.

So, no, you do not need to switch over yet, though I imagine they'll continue trying to push you towards QBO.

As to what QBO is, it is a significantly weaker version of QuickBooks Desktop and getting weaker all the time. For examples, browse this forum and you'll see several complaints about their changes.

You don't have to pay for both, though I imagine they'd be happy to take your money.