A program should appear when you click its icon, whether it’s open or not-just as on an iPhone or an iPad. In an ideal world, this distinction should be irrelevant. In macOS, Apple combined both functions into a single strip of icons called the Dock.Īpple’s thinking goes like this: Why must you know whether or not a program is already running? That’s the computer’s problem, not yours. The other kept track of which programs were open at the moment for easy switching, like the taskbar (Windows) or the Application menu (Mac OS 9).

One listed unopened programs until you needed them, like the Start menu (Windows) or the Launcher (Mac OS 9).

For years, most operating systems maintained two lists of programs.