How to Recognize Apps, Windows and the Parts of a Window on a Mac

What you need: A Mac that you have signed in to. These steps use Finder, the app that shows your files and folders, as the example app.

Steps

1. Look at the whole screen. The picture behind everything is the desktop, the row of words across the top edge is the menu bar, and the row of app icons is the Dock. They belong to the Mac itself, so they stay on the screen when every window is closed.
2. Click Finder, the blue and white smiling face at the left end of the Dock: move the pointer onto it, then press the mouse button (or the trackpad) once and let go. A window appears: a rectangle with its own edges, showing files and folders. Finder is an app, and this rectangle is one of its windows. The small dot below the Finder icon in the Dock shows that the app is open.
3. Look beside the Apple logo at the left end of the menu bar. The name Finder appears there in bold, followed by Finder's menus, such as File and Edit. The menu bar always shows the menus of the app in front, the one you are using. When you click a window of another app, that app's name and menus appear here instead.
4. Look at the strip along the top of the window, the title bar. It shows the name of the open folder, such as Recents. To move the window, put the pointer on an empty part of the strip, away from its buttons, hold down the mouse button, slide the mouse, and let go. On a trackpad, press down until you feel a click and keep pressing while you slide your finger, then lift it. The window moves with the pointer.
5. Look at the upper-left corner of the window. Three round buttons sit side by side. The red button closes the window. The yellow button minimizes it: the window shrinks into the Dock without closing. The green button makes the window fill the whole screen and hides the menu bar and the Dock. Do not click them yet.
6. In the menu bar, click File, then New Finder Window. A second Finder window opens in front of the first. Both windows belong to the one Finder app, which still has one icon in the Dock.
7. Click the yellow button on the front window. The window shrinks into the Dock, near the Trash at the right end. Click its small picture in the Dock, and the window comes back to where it was.
8. Look along the right edge of the window. When a window holds more than it can show, a scroll bar there lets you move through the rest. On many Macs it appears only while you scroll, and fades away when you stop. To scroll, rest the pointer on the window, then roll the mouse wheel or slide two fingers up or down on the trackpad. If everything fits in the window, there is nothing to scroll.
9. Make the window bigger or smaller. Move the pointer onto the right edge of the window, until the pointer becomes an arrow with a point at each end. Hold down the mouse button, slide left or right, and let go. The window becomes narrower or wider.
10. Click the red button on the front window, then the red button on the other window. Both windows close, but Finder still appears in bold beside the Apple logo, and the dot below its icon stays: closing an app's windows does not quit the app. Finder always stays open. Many other apps, such as Notes, also stay open after their last window closes, until you quit them as in How to Close a Window and Quit an App on a Mac. A few, such as System Settings, quit when their window closes.

Expected result: Both Finder windows are closed, Finder still appears beside the Apple logo in the menu bar, and the desktop, the menu bar and the Dock are still on the screen.