Open the "Mission Control" settings in System Preferences to see what key sequence you have assigned to "Application Windows". While you are there you might also click "Hot Corners..." and check if "Application Windows" is assigned to a hot corner.
Invoke "Application Windows" and it will show you all the visible windows of the current application tiled so you can see them all, and it will show you all the minimized windows of the current application across the bottom of the screen. (Some applications, such as TextEdit and BBEdit also show recent documents there).
While in the "Application Windows" ctrl-tab cycles between all open apps while remaining in "Applications Windows" view.
Invoke "Application Windows" and it will show you all the visible windows of the current application tiled so you can see them all, and it will show you all the minimized windows of the current application across the bottom of the screen. (Some applications, such as TextEdit and BBEdit also show recent documents there).
While in the "Application Windows" ctrl-tab cycles between all open apps while remaining in "Applications Windows" view.