When you’re working you probably want to remove every distraction that keeps you from being focused. For some people that includes hiding the Dock as well.
Here is how to hide the Dock in Mac OS X:
You can hide it easily by clicking on the Apple menu in the top left corner of your screen, and then selecting Dock -> Turn Hiding On.
This will instantly hide your Dock; however, keep in mind that when you hover over the Dock area with your mouse it will temporarily popup again.
Alternatively you can hide and reveal it by pressing Command + Option + D.
Hiding the Dock can give you additional screen real estate and remove the clutter, thus helping you remain more focused on your work.