“Previous window” can mean three different things on a Mac: the last application, the last window inside the current app, or the last project context. Choose the shortcut only after you identify which history you want.
Return to the previous application
Press Command-Tab once and release to move between recently used applications. Hold Command to inspect the application list, and use Shift-Tab to move backward through it. This route selects an app, so the window that appears is determined by that app and macOS state.
If you stayed inside one application, use Command-backtick to cycle its windows. This is a window-level route, but it may not behave like a strict two-item history when several windows are open.
Handle minimized, full-screen, and closed targets
If the app activates but no window appears, check whether the target is minimized, full screen on another Space, or closed. Mission Control exposes Spaces and open windows; the Dock and the app’s Window menu offer other recovery paths.
A closed resource is no longer a switching target. Reopen it from the app’s recent items, a file path, or a saved link.
Make project return explicit
When “previous” means the work you left before an interruption, record the project and next action instead of relying on recency order. A project group can narrow the windows across several apps, while a short task identifies the restart point.
Wallo’s keyboard path chooses a goal and then one of its current windows. It does not maintain a universal back stack for every tab, window, and application. Use native recency for quick app return and a named project for deliberate context return.