Using the Dock:
At the bottom side of the screen a bar of icons will be available called the Dock. On your Mac it provides you an easy access many of the apps such as Safari, Mail and Messages. It enables you to add your own documents apps and the folders to the Dock too.
If you need to use any item in the Dock you just need to click its icon. Click the iTunes icon in order to listen the music by opening the iTunes. Click the Mail icon to check your email.
Illuminated dash will be displayed by the Dock when an application is open beneath the icon of the application. Click the icon in the Dock to make any current running applications active one.
Organizing the Dock:
On the left side the Dock keeps the apps. On the right side of the Dock the folders, minimized windows and documents are kept. You can see a vertical separator line when you look closely and that separates these two sides.
When an icon appears on the Dock and if you need to rearrange, then you just need to drag it to another location in the Dock. The Finder and the Trash are the special items, so at the end of the Dock they are always available.
Adding and removing Dock items:
Click the Launchpad icon in the Dock if you need to add any application to the Dock. Then from the Launchpad you need to drag that app icon. Now the icons in the Dock will be moved aside to the new item. If you want to add a folder or the file to the Dock, then you just need to drag its icon from the Finder window and on the Dock you need to drop it.
From the Dock if you need to remove the item, then just drag the icon by an inch and wait for a couple of seconds. Then you need to release the icon and in the poof of the smoke it will disappear.