A maximized or filled Mac window remains a desktop window; a full-screen window occupies its own Space. That difference affects the menu bar, Dock, neighboring windows, and how you navigate back.
Use Fill for a larger desktop window
Choose Fill from the green-button menu or supported Window menu to expand the window within the desktop area. Apple’s current guidance says the menu bar and Dock remain visible for a maximized window. Other windows remain part of the same desktop and can be brought forward normally.
Fill is useful when you want more working area but still need desktop switching, drag-and-drop, or quick access to another overlapping window.
Use Full Screen for a dedicated Space
Full screen expands the app across the screen and places it in the Spaces model. The menu bar and Dock can hide until the pointer reaches their edges, depending on settings. Move between full-screen apps and desktops through gestures, Mission Control, or Space shortcuts.
Choose by navigation cost
| Need | Better starting choice |
|---|---|
| Keep other desktop windows nearby | Fill/maximize |
| Dedicate the display to one window | Full screen |
| Two apps in a dedicated pair | Split View |
| Several resizable desktop regions | Tiling |
Some applications use Zoom according to their content rather than filling every available pixel. Test the actual app. A project group records window membership; it does not determine whether the window is filled or full screen.