As others have stated, the cleanest option for a single monitor setup is to either share a specific window, or start making use of multiple virtual desktops, sometimes referred to as workspaces. Windows, Mac, and Linux are all capable of it, now - the only difference is how you set up, arrange, and navigate them.

Linux options offer the most versatility, Mac's implementation is a decent balance between ease of use and scalability (with caveats), and the Windows native implementation is the newest entrant to this playing field... but it's an adequate offering that gets the job done for this use case.