The most intuitive difference between the OS X system and the Windows desktop is the translucent dock bar, where Mac OS X's Dock provides a convenient portal for you to launch applications, access the most used files and folders, and by default the dock of OS X is placed at the bottom of the screen.
When you first enter the OS X Yosemite Desktop, there are many applications built into the dock, how do you use it? In fact, you can not only customize what is displayed in the dock, but you can also adjust the size, location, and other "fun" things in the dock.
1. Add applications, folders, and files to the Dock
Open your Application folder.
Find the application you want to add.
Click and hold the application icon and drag it to the dock (when you move the icon to the dock, the existing application icon in the dock will move to both sides to make room).
Let go and leave the application in the Dock.
Repeat the above steps to add more applications to the Dock.
Note: You can also add folders or individual files (folders and files will be added to the right of the Dock split line).
2. Remove applications, folders, and files from the Dock
Quit the application before you try to remove it from the dock, because the open application icon will always appear on the dock.
Click and hold the application icon on the Dock.
Drag it outward to leave the Dock.
After a moment OS X will pop up saying "Remove" and drop it.
Repeat these steps to delete files or folders and files that have been added to the Dock.
3. Change the size and position of the Dock
You can resize the dock, resize the icon (when you move your mouse pointer over the dock), adjust the dock's position (left, bottom, or right), and adjust the animation effect of the minimized window.
Turn on system preference settings.
Click the Dock option icon.
Slide the slider to resize the Dock and adjust the magnification of the mouse hover over it.
Click to select the location you want the Dock to display.
Click to select the minimized window animation effect.
4. Extra Tips
You can move the mouse pointer to the split line on the right side of the dock (when the mouse light becomes a double-headed arrow, click and drag to resize the dock).
You can also hold down the Shift key while you press and hold the split line and then drag the dock freely to dock it at different edges of the screen.
5. Add a blank split area to the Dock
Open the terminal application and enter the following command:
Defaults write Com.apple.dock persistent-apps-array-add ' {' tile-type ' = ' spacer-tile ';} '; Killall Dock
Press the return key.
Repeat the steps above to add multiple blank areas to the Dock.
Close the terminal application.
Note: The blank area is like a transparent icon, you can click and hold it to drag to the position you like; If you don't like it, drag it outside the dock for a moment to remove it (just like deleting an application icon from the dock).
6. Add "Recently used" stack to Dock
Open the terminal application and enter the following command:
Defaults write Com.apple.dock persistent-others-array-add ' {tile-data ' = {"List-type" = 1;}; "Tile-type" = "Recents-tile";} '; Killall Dock
Press the return key.
Close the terminal.
Note: The most recently used stack will appear on the right side of the Dock's split line, near the wastebasket. You can further make a selection of the View display (list, grid, etc.). If you no longer need it, simply drag it out of the Dock to remove it.