The dock at the bottom of the macOS system desktop (previously called the Dock bar) is a place to quickly open applications and files. We can fix commonly used applications on the dock so that we can quickly launch applications. The last two icons in the Dock are the "Download" icon and the "Trash" icon. Click the left mouse button on the "Download" icon to quickly expand the files in the download folder and open them.
Dock application management It
is very simple to manage the icons on the macOS Dock. Just use the mouse cursor to drag the application icons we want to fix onto the Dock to fix them, and drag the icons to sort. After dragging the folder to the Dock, you can view the folder by stacking the folders.
Application shortcut menu
Right-click on the Dock icon or hold down the Control key and then click the left button to pop up a shortcut menu for performing other operations of the application, such as opening or closing the App, opening recent documents, etc. Right-click on the "Trash" icon to quickly empty the Trash. If an application appears stuck and cleared, you can right-click on the application icon in the Dock at this time, and then click "Force Quit" to close the stuck application.
Recently used applications are
introduced on the right side of the dock of the latest macOS 10.15 and later macOS systems. The icons of the three recently opened applications that are not fixed on the dock will be displayed for us again Open it quickly.
Preferences
Put the mouse cursor on the dividing line "|" of the dock, a double-arrow “↕” cursor will appear on the dividing line, and then hold down the left mouse button and drag up and down to change the size of the dock. Click the mouse on the dividing line Right-click to open the Dock preferences menu, and adjust the position of the Dock on the screen. For example, you can place the Dock on the bottom, left, or right of the screen.
Shortcut keys
Use shortcut keys to quickly access the Dock: Press Control+F3 at the same time (press Control+Fn+F3 on a Mac notebook) to locate the Dock. Then press the left and right direction keys of the keyboard to switch between icons, and press the Return key to open the currently selected application.
Application mark
The red mark on the icon in the Dock represents the notification or to-do of the application. For example, the red mark on the "Mail" icon in the Dock indicates that you have new emails to read.
Tips for using macOS Dock:
Open the file in the App: Drag the file to the App icon. For example, to open a document created in Pages, drag it to the Pages icon in the Dock.
Show the application in the Finder: Hold down the Command key and click the icon of the item.
Switch to the previous App and hide the current App: Hold down Option and click the current App icon.
Switch to another app and hide all other apps: hold down the Option-Command key and click the app icon you want to switch to.