https://macmost.com/e-1854 When you click the red button at the top left corner of a window on a Mac, you close that window. But sometimes this also quits the app entirely. There is a logic behind this, based on how the app operates. Apps that allow multiple windows for multiple documents usually only use the red button to close a window. But apps that normally operate with a single window and have no other reason to stay open, will quit.