See open windows and spaces in Mission Control on Mac
Mission Control shows all the windows open on the desktop of your Mac, arranged in a single layer so it’s easy to spot the one you need. Apps that are in full screen or Split View, and desktop spaces you created, are shown as thumbnails in the Spaces bar along the top edge of the screen.
Enter or leave Mission Control
From a trackpad: To enter, swipe up using three fingers. To leave, swipe down. You can turn off or change the trackpad gesture in Trackpad settings.
From a keyboard: To enter or leave, press the Mission Control key
(or use the Control Strip) or press Control-Up Arrow. You can change the keyboard shortcut in Desktop & Dock settings.
If you enter Mission Control on a second display, only the open windows and spaces you’re working with on that display are shown.
Show or move all open windows
Show all open windows for the current app: Press Control-Down Arrow. If App Exposé is enabled in Trackpad settings, you can also swipe down with three or four fingers. To return to the desktop, press the keys again or swipe up.
Show all open windows grouped by app: In Desktop & Dock settings, turn on “Group windows by application” below Mission Control. Then press Control-Down Arrow.
Move open windows aside to show the desktop: Press Command-Mission Control
or spread your thumb and three fingers apart on the trackpad. To move the windows back, press the keys again or pinch your thumb and fingers together on the trackpad.
You can change the keyboard shortcuts in Desktop & Dock settings and turn off or change the trackpad gestures in Trackpad settings.
Copy or move items using Mission Control
If you have many windows or apps open and you need to copy or move items between them or to the desktop, Mission Control can make it easier.
Copy text or an image between windows: After you copy the item, enter Mission Control to show all open windows, click a window to go to it, then paste the item.
Copy a file or folder to the desktop: After you copy the item, press Command-Mission Control
to move all windows aside and show the desktop, then paste the item. Press the keys again to move the windows back.Move a file or folder to the desktop: Start dragging the item from a window, press Command-Mission Control to move all windows aside and show the desktop, then drop the item. Press the keys again to move the windows back.
Tip: To quickly use two apps in Split View, just drag a window from Mission Control onto the thumbnail of a full-screen app in the Spaces bar, then click the thumbnail.
You can change options and set shortcuts for using Mission Control in Desktop & Dock settings. On your Mac, choose Apple menu 
in the sidebar and adjust settings on the right. (You may need to scroll down.)