Most people learn Cmd+Tab in their first week with a Mac and stop there, which is a shame, because macOS has several other ways to get to the window you want, some of them faster than Cmd+Tab for the exact problem it is bad at. Here is the full set.
Cmd+Tab switches apps, not windows
Hold Command and press Tab to open the app switcher, a row of icons for your recently used apps. Keep Command held and tap Tab again, or use the arrow keys, to move along the row, then release to switch. Command+Shift+Tab moves backward through the same row. This switches between whole apps: it brings that app's frontmost window forward, whichever window that happens to be.
Cmd+backtick switches windows within one app
Command and the backtick key, just above Tab, cycles through the open windows of the app you are already in, without leaving it. If Finder, Safari or a chat app has several windows open and Cmd+Tab keeps landing you on the wrong one, follow it with Cmd+backtick to step through that app's own windows one at a time. Command+Shift+backtick goes backward.
Mission Control: see everything at once
Press Control+Up Arrow, or swipe up with three or four fingers on the trackpad, to open Mission Control. It lays out every open window across every desktop, shrunk down and grouped by app, so you can scan the whole picture and click straight to the window you want instead of cycling toward it.
Moving between full-screen apps and Spaces
If an app is in full-screen mode, or you keep separate desktops for separate projects, Cmd+Tab and Mission Control are not the fastest route back to it. Press Control+Right Arrow or Control+Left Arrow, or swipe left or right with three or four fingers on the trackpad, to step directly between full-screen apps and Spaces in order, without opening Mission Control first.
Toggling between screens, which is two different questions
People ask how to switch screens on a Mac meaning one of two unrelated things. If you mean Spaces and full-screen apps, that is Control+Right Arrow and Control+Left Arrow, covered above. If you mean physical displays, there is no built-in shortcut that throws a window onto another monitor: you drag it across, or you use a third-party tool's next display command. Rectangle, Magnet and Raycast all have one. macOS itself does not, which surprises people every time.
Worth knowing which of the two you actually want before you install anything, because they need different tools. The map of what each kind of window tool does is in Mac window managers, compared, and multi-display behavior specifically is in using multiple monitors with a Mac.
If you meant switching from Windows back to macOS
A fair number of people searching this are not asking about windows at all, they are asking about Windows, so here is the short version. On an Intel Mac running Windows through Boot Camp, the Boot Camp item in the Windows system tray has a Restart in macOS option, or you can hold the Option key while the Mac starts up and pick the startup disk. On Apple silicon Macs there is no Boot Camp, so Windows runs inside virtualization software, and you leave it the same way you leave any app: switch out of it with Cmd+Tab, or quit it. Everything else on this page is about app windows on macOS.
App Exposé: one app at a time
Press Control+Down Arrow, or swipe down with three fingers on the trackpad, to see only the windows belonging to the current, frontmost app, spread out so you can pick between them. It is the same idea as Mission Control, narrowed to a single app, which is faster when that app is the one with too many windows open.
Stage Manager and the Dock
With Stage Manager on, your recent apps sit as small thumbnails along the left edge of the screen; click one to bring it forward. Without Stage Manager, a single click on a Dock icon brings that app's frontmost window forward, and clicking and holding (or right-clicking) a Dock icon shows a list of that app's open windows so you can jump straight to a specific one.
A hidden gem: restoring a minimized window
If the app you are switching to has nothing open but a minimized window, hold the Option key while you release Cmd+Tab on it, and macOS brings that window back instead of just activating the app with nothing visible on screen. It saves a trip to the Dock to click the minimized window separately.
Switching is easier when windows stay put
All of the above assume your windows are roughly where you expect them. That assumption breaks the moment you unplug a monitor: macOS piles every window from the disappearing display onto whatever screen is left, and does not undo that when the monitor comes back. Cmd+Tab and Mission Control still work fine, they just take you to a pile instead of the layout you had a minute ago. We cover why in why your Mac windows move when you unplug a monitor.
Putback keeps every window in its place across display changes, so switching stays predictable: Cmd+Tab, Mission Control or a Dock click always land on the window where you left it, on whichever screen it belongs on. It pairs naturally with however you arrange windows in the first place, whether that is snapping or split screen.
