#alternatives
Wormhole vs Beam: one Mac's window on another
Both open a window from another Mac on this one as a window of its own, with its own Dock icon. Wormhole needs no account and is a one-time license; Beam needs a sign-in, is sold as a subscription or a lifetime license, and adds browser share links.
Wormhole vs macOS Screen Sharing
Screen Sharing, which comes with macOS, shows the other Mac's whole screen inside one window. Wormhole opens a single window from the other Mac as a window of its own here, with its own Dock icon, and needs the app on both Macs.
Four ways to use another Mac's apps
To see the other Mac's whole screen, use Screen Sharing, which comes with macOS, or a remote desktop app such as Jump Desktop. To bring over just one window as a window of its own, use an app built for that: Beam or Wormhole.